Category: Climate Change Impacts

The scale of the climate challenge facing Myanmar

The scale of the climate challenge facing Myanmar

By Georgina Wade

Today, Myanmar is in the midst of a fight that will determine the future of its democracy. While this inevitably demands the full attention and energy of the population, the future holds other challenges of its own. The military takeover came just as the government was preparing for a crucial year for climate change, culminating in the COP26 UN Climate Conference in Glasgow, UK, in November. According to the 2020 Global Climate Risk Index, Myanmar is the world’s second most disaster-prone country, exposed to multiple climate-related hazards, including floods, cyclones, landslides, and droughts. Climate impacts will be felt through the whole economy and will touch all aspects of society. Building resilience will require the government to put climate change at the heart of its decision-making processes and development plans. Only an integrated approach that recognises the interconnected nature of climate risks will be effective.

Over the past decade, Myanmar has made some progress. The country had decreased its poverty rate from 48.2 per cent in 2005 to 24.8 per cent in 2017. Whilst this represents good progress, climate change threatens further development as it will impact all sectors in Myanmar, including agriculture, transport and energy.

Agriculture

Agriculture remains the backbone of Myanmar’s economy, employing over half of the labour force. Agricultural reforms have seen Myanmar reach a state of self-sufficiency in staple foods, and the country had experienced a rapid decline in malnutrition figures in just a few decades. For instance, the prevalence of stunting among children below the age of five had reduced from around 40 per cent in the 1990s to less than 30 per cent in 2016.

Despite this progress, seasonal food insecurity remains a concern across Myanmar. Kundhavi Kadiresan, Assistant Director-General and Regional Representative for Asia and the Pacific of the UN Food and Agriculture Organization said in a speech in 2019 that “much work remains to be done for Myanmar to achieve SDG-2, the Sustainable Development Goal of zero hunger by 2030.” Climate impacts threaten to make this goal even harder to reach. 

Increased rainfall during the wet season and decreased rainfall during the dry season may reduce agricultural production for key crops. More frequent extreme heat and higher average temperatures may also lead to crop failures, reduce productivity, or alter staple crops’ nutritional content. Despite Myanmar’s economic progress, its reliance on the agricultural sector makes over half of the labour force highly vulnerable to climate change impacts. 

Transport

Productivity is linked to connectivity – efforts to improve transport connectivity in Myanmar present opportunities to boost trade, growth and regional integration. When transport systems are efficient and reliable, they provide economic and social opportunities and benefits that result in positive multiplier effects such as better accessibility to market and employment.

Research suggests that increased public spending on transport infrastructure over the next decade could reduce logistics costs by around 30 per cent and increase annual GDP by up to $40 bn. Energy, water and telecommunications infrastructure also face increased risk from physical damage and disruption caused by storms, floods and other hazards becoming more frequent and intense due to climate change.

Energy

A reliable supply of energy is fundamental for Myanmar’s continued economic development. Myanmar has aggressively pursued hydropower as a way of meeting increasing demand whilst limiting its carbon emissions. Hydropower, the world’s leading renewable energy resource for electricity generation, accounted for 75 per cent of the country’s electricity consumption in 2017.

Over-reliance on hydropower holds its problems. Heatwaves and an increasing number of extreme heat days could increase energy demand for air conditioning and industrial cooling. At the same time, droughts and change in river flows due to erratic rainfall may affect hydropower energy generation. The costs of power outages will be felt across the whole economy, as industrial and commercial rely on a continuous power supply.

Diversified power systems that draw on multiple forms of renewable energy, such as solar and wind power, are more resilient to climate impacts and can deliver energy closer to the communities that they serve. Nature-based solutions, such as reforestation, can also reduce the risk to hydropower by regulating water flow and stabilising the soil, preventing landslides and improving water quality.

When Myanmar is able to look towards the future once more, it must take steps to build its climate resilience to achieve its development objectives. An integrated approach is required to manage these interconnected challenges.

Climate change must be integrated into decision-making across all government departments. For it to be taken seriously, it must also be understood as a priority issue at the highest levels including within the Ministry of Planning and Finance. A broader process of engagement with Myanmar’s people is also required to ensure the country can move forward towards a future in which everyone can share. There is much reconciliation to do in the meantime to achieve this.


Cover image: Landslide in Myanmar. Climate change will make these events more common.  By Sukun, 2017

Infographic references:

i.Food Security Cluster (FSC); Myanmar

ii. The Myanmar Times (2020); Extreme weather in Myanmar’s Magwe breaks temperature record

iii. Frontier Myanmar (2019); The National League for Democracy’s power fail

iv. Global Witness (2020); Myanmar jade mine disaster highlights government inaction

Half a billion people may face heat of 56°C by 2100

Half a billion people may face heat of 56°C by 2100

By Tim Radford

Take today’s heat, apply mathematical logic and consider a murderously hot future, 56°C by 2100, for hundreds of millions.

LONDON, 29 March, 2021 − Many millions of people − among them some of the world’s poorest − will be exposed to potentially lethal temperatures on a routine basis. At worst, the mercury could reach 56°C by 2100.

Even if the world keeps its most ambitious promise and contains global heating to no more than 1.5°C above the global average normal for most of human history, the future looks distinctly menacing.

And if the world doesn’t quite get there, and annual average temperatures − already 1°C above the historic norm − rise to 2°C, then vast numbers of people in South Asia will find themselves exposed to deadly conditions at least three times as often.

As the researchers make this sober warning in one journal, researchers on the same day in yet another journal make a simple prediction about the cost of ignoring such warnings altogether, to go on burning ever more fossil fuels and destroying ever more tracts of the natural world.

If this happens, then people in the Middle East and North Africa will be hit by a new category of thermal menace: the arrival of super-extreme and ultra-extreme heatwaves.

Target far exceeded

Which means that by the end of this century, more than half a billion people could be exposed to temperatures as high as 56°C, not just for days, but for weeks. The hottest temperature so far ever recorded on Earth was 54°C, in Death Valley, California in 2020.

In 2015, almost all of the world’s nations met in Paris and vowed to contain global heating by the century’s end to “well below” a maximum of 2°C. In fact, the less explicit intention was to contain the mercury’s rise to no higher than 1.5°C.

So much for the vow: the latest evidence is that, on the basis of the national declared intentions so far, global temperatures will rise far higher than the 2°C target. And summer − defined as the hottest 25% of the year − could by the century’s end last almost six months.

A new computational study in Geophysical Research Letters warns that the 1.5°C target could be passed by 2040, in just two decades. And with higher average temperatures over longer periods, there will inevitably be higher than average extremes of temperature, more often, for longer periods, and over wider ranges.

“The need for adaptation over South Asia is today, not in the future. It’s not a choice any more.”

The outcome could be devastating for the countries of South Asia − India and Pakistan, Sri Lanka, Bangladesh and Burma among them − as the thermometer rises and the humidity increases. Researchers have warned for years that at a certain level of heat and humidity − meteorologists call it the “wet bulb” temperature − humans cannot labour productively.

That level is 32°C. At a wet bulb temperature of 35°C, humans cannot expect to survive for long. Some parts of the region have already felt such temperatures with a global average rise of just over 1°C: in 2015, at least 3500 people in Pakistan and India died from causes directly related to extreme heat.

At 1.5°C the consequences could be significantly worse, and at 2°C, the scientists say, the hazard will have been amplified by a factor of 2.7: almost threefold. South Asia could later this century be home to more than two billion people: of the working population, 60% are now engaged in agricultural labour out of doors, and many millions live in crowded cities and in severe poverty. The region should prepare itself for a dangerously hot future.

“The future looks bad for South Asia,” said Moetasim Ashfaq, of the US Oak Ridge National Laboratory, one of the authors, “but the worst can be avoided by containing warming to as low as possible. The need for adaptation over South Asia is today, not in the future. It’s not a choice any more.”

That heat extremes are potentially lethal, that the people of South Asia are potentially at risk, and that an enormous proportion of the planet’s population will be exposed to dangerously high temperatures is not in dispute: the questions now are about the degree of danger, and its extent.

Ultra-extreme heat

Once again, the statisticians have been at work, and the answer in the journal Climate and Atmospheric Science is: it will be much worse, over a vaster region and for a very large number of people in the Middle East and North Africa.

Their calculations suggest that temperatures could reach as high as 56°C, and even more than 60° C in sweltering cities. Such heat extremes could endure for weeks.

So within the lifetimes of those alive today, about half the region’s population − that is, about 600 million people − could face extreme temperatures of around 56°C by 2100 every summer.

The researchers put their message with unusual forthrightness in the headline: “Business-as-usual will lead to super- and ultra-extreme heatwaves in the Middle East and North Africa.” − Climate News Network


This article was originally posted on The Climate News network.
Cover photo by Sarah Lachise on Unsplash
How droughts and floods lead to migration — and 7 things governments can do to help

How droughts and floods lead to migration — and 7 things governments can do to help

By Cameron Fioret and Nidhi Nagabhatla

Extreme water events affecting water for drinking, cooking, washing and agriculture drive migration all over the world. Earlier this year, cyclone Eloise battered Mozambique, displacing 100,000 to 400,000 people and weakening the country’s infrastructure. People displaced by the storm were in need of food, hygiene kits and personal protective equipment (PPE).

Cyclones are just one form of extreme water events that will play out more frequently and adversely as water crises worsen with climate change. Water extremes and climate change will cause more than one billion people to migrate by 2050.

Migration will be spurred by drought, as in the Sahel in Africa, shortsighted water management, as in the Aral Sea region of Kazakhstan and Uzbekistan, flooding, as in Bangladesh and small island developing states, and other extremes like cyclones.

Addressing water-driven migration will require research that crosses borders and research boundaries. As climate change continues to cause serious displacement and socio-political upheaval, governments must take action to minimize the effects on people vulnerable to migration.

The stakes of water-driven migration

Water-driven migration is a crucial challenge for people living in vulnerable and unstable regions. Water stress acts as a direct or indirect driver of conflict and migration. As water and climate extremes become worse, more people will face water crises and be forced to migrate.

For instance, take the famous case of the Aral Sea that shrank to 9,830 square kilometres in 2017 from 55,700 square kilometres in the 1970s. More than 100,000 people migrated due to collapse of agriculture, fisheries, tourism and increased illnesses such as tuberculosis and diarrhea.

Satellite imagery of the Aral Sea over time.
More than 100,000 people were displaced from the area around the Aral Sea from 1970 to 2017 due to water mismanagement. (Landsat data mapped by UNU-INWEH), Author provided

Vulnerable populations bear the brunt of impacts on water availability, food production, livelihoods and income. As water and care providers, women and girls carry the burden of fulfilling water needs for their households and families. Women and girls also bear disproportionate health impacts of water crises as more hours are spent organizing household water needs.

A recent report explains that political instability, chronic poverty and inequality and climate change worsen water-driven migration. With at least 33 nations set to face “extremely high (water) stress” by 2040, it is more pressing than ever to face this problem with a strategic approach.

A seven-point strategy

Countries that have committed to the United Nations Sustainable Development Goals could address water-driven migration through SDG 16 (peace, justice and strong institutions). Policy can be aligned with SDG 16 along a seven-point strategy:

  1. Address the connection between water ownership, distribution and migrationWater ownership and distribution likely influence migration at local, regional and global levels. To capture the scope of water issues, future research must strike a balance between scientific and social aspects of water.
  2. Understand how water crises influence migration: Causality is important in addressing migration. Land, water and human security issues could serve as a base for outlining a preventative outlook for new and emerging migration pathways.
  3. Integrate diverse perspectives in water migration assessments: Water co-operation treaties must integrate under-represented, marginalized and racialized migrant voices. The United Nations University’s Institute for Water, Environment and Health has developed an approach to aggregate the causes and consequences of water-driven migration. This framework can help policy-makers interpret migration in diverse socio-ecological, socio-economic, and socio-political settings.
  4. Assess water, migration and development practices through participatory, bottom-up and interdisciplinary approaches: Research should be participatoryapplicable between disciplines and socially inclusive to complement scientific, descriptive methods. Nuanced facts of the diverse influences that shape migration can provide understanding to build resilience among vulnerable populations.
  5. Manage data, information and knowledge: Researchers need updated data to examine how water crises are linked with human migration. To close the gaps, the UN has pointed to the need to improve capacity for data analysis within and between countries. Also, there must be stronger co-ordination at the state, regional and international levels to share best practices.
  6. Apply a gender-sensitive lens: The economic, health and societal effects of water-driven migration affect men, women and children differently. Filling these knowledge gaps will require a gender-sensitive approach to assess causes and effects. Namrata Chindarkar, a water and public policy researcher, has argued that comprehensive and holistic investigations of the states people come from, end up in and transit through must be gender-sensitive if they are to be inclusive.
  7. Understand water, migration and peace: There is potential for using water security to promote peace. Broader approaches could help examine key links between water, migration and peace.

Policy-makers must prepare for the consequences of water crises by adopting improvements that address the concerns of those vulnerable to migration. The seven-point strategy calls for policy-makers to use strategic and integrated approaches between disciplines. Research that maps causes, risks and impacts at the local, regional and global levels can strengthen water migration policies.


Read the original article by The Conversation here. CC BY-ND 4.0
Cover photo by Atul Pandey on Unsplash
Sea levels are rising fastest in big cities – here’s why

Sea levels are rising fastest in big cities – here’s why

By Sally Brown and Robert James Nicholls

It is well known that climate-induced sea level rise is a major threat. What is less well know is the threat of sinking land. And in many of the most populated coastal areas, the land is sinking even faster than the sea is rising.

Parts of Tokyo for instance sank by 4 metres during the 20th century, with 2 metres or more of sinking reported in Shanghai, Bangkok, and New Orleans. This process is known as subsidence. Slow subsidence happens naturally in river deltas, and it can be accelerated by the extraction of groundwater, oil or gas which causes the soil to consolidate and the surface to lose elevation.

Subsidence leads to relative sea level rise (sea level rise plus land sinking). It turns croplands salty, damages buildings, causes widespread flooding and can even mean the loss of entire coastal areas.

Subsidence can threaten flooding in low-lying coastal areas, much more so than rising sea levels, yet scientists are only just realising the global implications of the threat with respect to coastal cities.

In fact, while the average coastal area experiences relative sea level rise of less than 3mm per year, the average coastal resident experiences a rise of around 8mm to 10mm per year. This is because so many people live in deltas and especially cities on deltas that are subsiding. That’s the key finding of our new research, where we analysed how fast cities are sinking across the world and compared them with global subsidence data including less densely populated coastlines.

Map showing relative sea level rise in 23 coastal regions around the world.
When weighted by population, relative sea level rise is worst in south east Asia, followed by south and east Asia, and the southern Mediterranean. Nicholls et alCC BY-SA

Our finding reflects that people often choose to live in river deltas, floodplains and other areas that were already prone to sinking, and in doing so will further enhance subsidence. In particular, subsiding cities contain more than 150 million people in the coastal zone – that’s roughly 20% of people in the world who live by the sea. This means relative sealevel rise will have a more sudden and more severe impact than scientists had originally thought.

Here are a few of the most affected cities:

Jakarta

The Indonesian capital Jakarta is home to 10 million people, and is built on low-lying land next to the sea. Groundwater extraction caused the city to sink more than three metres from 1947 to 2010 and much of the city is still sinking by 10cm or more each year.

Subsidence does not occur evenly, leading to uneven risks that make urban planning difficult. Buildings are now flooded, cracks are appearing in infrastructure which is being abandoned.

Jakarta has built higher sea walls to keep up with the subsidence. But since groundwater pumping continues, this patching-up policy can only last so long before the same problems occur again. And the city needs to keep pumping since groundwater is used for drinking water. Taking water, the very thing that humans need to survive, ultimately puts people at risk from inundation.

The battle against subsidence is slowly being lost, with the government proposing in 2019 to move the capital to a purpose-built city on the island of Borneo more than 1,000km away, with subsidence being one of many reasons.

Shanghai

Developing rapidly in the past few decades, and now with a population of 26 million, Shanghai is another sinker. The city has maximum subsidence rates of around 2.5cm a year. Again this is mostly caused by lowering groundwater levels, in this case thanks to drainage to construct skyscrapers, metro lines and roads (for instance Metro Line 1, built in the 1990s, caused rapid subsidence).

Body of water in front of lots of skyscrapers.
Shanghai is found where the river Yangtze meets the sea. John_T / shutterstock

If no additional protection is built, by 2100 this rate of subsidence and sea level rise mean that a storm surge could flood around 15% of the city.

New Orleans

In New Orleans, centuries of embankments and ditches had effectively drained the city and sunk it, leaving about half of it below sea level.

Map of New Orleans with shaded areas below sea level.
Much of New Orleans is below sea level (red) and relies on sea walls to stay dry. The Data Center, New OrleansCC BY-SA

When Hurricane Katrina breached the levees in 2005, the city did not stand a chance. The hurricane caused at least US$40 billion (£29 billion) in damage and particularly took its toll on the city’s African American community. More than 1,570 people died across the state of Louisiana.

If the city had not subsided, damage would have been greatly reduced and lives would have been saved. Decisions that were made many decades or more ago set the path for the disasters that are seen today, and what we will see in the future.

There are no simple solutions

So what can be done? Building a sea wall or dike is one immediate solution. This of course stops the water coming in, but remember that the sea wall is sinking too, so it has to be extra large in order to be effective in the long-term. In urban areas, engineers cannot raise ground easily: that can take decades as buildings and infrastructure are renewed. There is no simple solution, and large-scale urban subsidence is largely irreversible.

Some cities have found “solutions”. Tokyo for instance managed to stop subsidence from about 1960 onwards thanks to stronger regulations on water pumping, but it cannot get rid of the overall risk as parts of city are below sea level and depend on dikes and pumps to be habitable. Indonesia’s bold proposal to move its capital city may be the ultimate solution.

Increased urbanisation especially in deltas areas and the demand for freshwater means subsidence will remain a pressing issue in the coming decades. Dealing with subsidence is complementary to dealing with climate-induced sea level rise and both need to be addressed. A combination of rising seas and sinking lands will increasingly leave coastal cities at risk.


This article was originally posted on The Conversation.
Photo by Mika Baumeister on Unsplash
Europe has grown drier over the last two millennia

Europe has grown drier over the last two millennia

By Tim Radford

Global heating may be to blame for the fact that Europe has grown drier over the last 2,000 years to a new high in 2015.

LONDON, 17 March, 2021 − Europe has grown drier, an outcome shown by the continent’s last five summers, which have been marked by drought that has no parallel in the last two millennia.

Researchers studied two kinds of evidence delivered by 27,000 measurements taken from 21 living oak trees and 126 samples from ancient beams and rafters, to piece together a precise picture of the climate of Germany, Switzerland and the Czech Republic over the last 2,110 years.

They report, after 2015, that drought conditions intensified suddenly, in ways that were beyond anything over that entire 2000-year tract of time. And, they add, “this hydroclimatic anomaly is probably caused by anthropogenic warming.”

Europe is also getting hotter. In 2003, 2015 and 2018 it was hit by severe summer heat waves and spells of drought that damaged plantations, crops and vines; the damage from drought was intensified by more virulent attacks from pathogens, insect outbreaks and tree death.

“Extreme conditions will become more frequent, which could be devastating for agriculture, ecosystems and societies as a whole”

In the baking summer of 2003, an estimated 70,000 people died because of extremes of heat. And, the researchers say, “a further increase in the frequency and severity of heat waves under projected global warming implies a multitude of harmful direct and indirect impacts on human health.”

In other words, things are bad now and are likely to get worse, according to a report by 17 British, European and Canadian researchers in the journal Nature Geoscience.

Dendrochronologists can and do routinely build up a picture of bygone temperatures by measuring the growth rings in trees: enough old living trees, and reliable knowledge about the felling of oaks for chateaux, cathedrals, sailing ships, fortresses and stockades can help pinpoint seasonal change on an annual basis.

But trees are also living chronicles of changes in carbon and oxygen isotope ratios − tiny atomic variations in the plant’s biochemistry − which provide evidence of rainfall and therefore a more precise picture of any growing season.

Wandering jet stream

The trees delivered mute evidence of very wet summers in 200, 720 and 1100 AD, and very dry summers in the years 40, 590, 950 and 1510 of the Common Era. But overall the big picture emerged: for the years 75 BC to 2018, Europe has slowly been getting drier.

Even so, the evidence from 2015 to 2018 shows that drought conditions in the area from which the trees were taken far exceeds anything in the previous centuries. The mostly likely explanation is the impact of ever-rising temperatures, driven by ever-higher greenhouse gas emissions from the ever-more profligate combustion of fossil fuels.

These temperatures are now considered high enough to affect the course of the stratospheric jet stream in ways that alter the long-term pattern of temperature and rainfall that defines a region’s climate.

“Climate change does not mean it will get drier everywhere,” said Ulf Büntgen, who holds research posts in the University of Cambridge, UK and the Czech Republic and Switzerland. “Some places may get wetter or colder, but extreme conditions will become more frequent, which could be devastating for agriculture, ecosystems and societies as a whole.” − Climate News Network


This article was originally posted on the Climate News Network.
Cover image by US Embassy, Paris (public domain), via Wikimedia Commons
Poorest people will suffer worst from cities’ heat

Poorest people will suffer worst from cities’ heat

By Tim Radford

As ever, the poorest people will most feel the heat in a hotter world. But a green growth initiative could help them.

As the summer thermometer soars, and the cities of the US Southwest are caught up in extremes of heat, the poorest people who live in the least prosperous districts may find their streets as much as 3°C hotter than those of the wealthiest 10%.

And in Los Angeles, one of the richest cities in one of the richest states of the world’s richest nation, citizens in the most heavily Latin-American districts could be as much as 3.7°C hotter than their white, well-heeled neighbours.

Excess heat is linked to heat stroke, exhaustion, respiratory and cardiovascular problems and of course death: one US group has identified 27 ways in which heat can kill, and several sets of researchers have independently established that potentially lethal heat waves are becoming more likelymore extreme and more widespread.

Californian geographers report in the International Journal of Environmental Research and Public Health that they mapped summer temperatures in 20 urban centres in California, Nevada, Utah, Arizona, Colorado, New Mexico and Texas.

“The study provides strong new evidence of climate impact disparities affecting disadvantaged communities”

They looked at the data for median household income, and for ethnic origin, to identify the ratio of Black, Latin and Asian populations in each.

They also took into account education levels. And then they looked at satellite data for radiant and atmospheric temperatures on the warmest summer days and nights.

The greatest disparities in street temperature were in California. But on average the poorest 10% of neighbourhoods in a conurbation would be 2.2°C hotter than the wealthiest 10% both on average summer days and during extremes of heat.

There is a term for this: the inner city becomes a heat island. As global temperatures rise, crowded cities become increasingly inhospitable. Paved streets and car parks absorb and retain the sun’s radiation.

Ending ‘thermal inequity’

The suburbs and the high-amenity residential districts will have tree-lined streets, private gardens, parks, flower displays, lawns and even fountains or pools, all to help lower the local temperatures.

Using the constrained language favoured by science journals, the authors write: “The implication would be that programs to increase vegetation within disadvantaged neighborhoods and reduce or lighten pavements and rooftops could help reduce thermal disparities between neighborhoods of different socio-economic characteristics.”

The researchers can hardly have been surprised by their own results: a look at published research had shown them that other groups have found evidence of what they call “thermal inequity” in Hong Kong, New York and Chicago, as well as in Santiago, Chile and in the crowded cities of Britain’s West Midlands.

“The study provides strong new evidence of climate impact disparities affecting disadvantaged communities, and of the need for proactive steps to reduce those risks,” said John Dialesandro, of the department of human ecology at the University of California Davis, who led the research. “There is a strong need for state and local governments to take action.” − Climate News Network


This article was originally posted on The Climate News Network.
Cover image by bantersnaps on Unsplash.
Heating of the Tasman sea warms up the climate of Antarctic Peninsula via changes in wind patterns, suggests new study

Heating of the Tasman sea warms up the climate of Antarctic Peninsula via changes in wind patterns, suggests new study

Heating of the Tasman sea warms up the climate of Antarctic Peninsula via changes in wind patterns, new study by Japanese and Australian scientists shows

The Antarctic Peninsula is melting faster than ever. In a recent study, scientists have revealed how heating in the Tasman sea causes warming of the West Antarctic region and leads to melting of ice and rise in sea levels. They suggest that wind streams flowing towards poles from the tropics play an important role in these oceanic and temperature variations. These findings can be helpful to populations that are vulnerable to sea level rise.

The melting of the Earth’s ice cover intensified in the 20th century, with glaciers and sea ice in the Arctic and Antarctic regions melting at alarming speeds. In fact, The Antarctic Peninsula (AP), which is the only landmass of Antarctica extending out past the Antarctic Circle, was found to be one of the most rapidly warming regions on the planet during the second half of the 20th century. This rapid change in climate has raised serious concerns of rising sea levels the world over.

Multiple factors have been associated with the melting of the ice cover: the primary factor being the greenhouse gas emissions from human activities that cause warming up of the atmosphere and the oceans and the consequent ice melting. Apart from this, atmospheric variations, ocean currents, and wind patterns also play a significant role. Now, a collaborative group of scientists from Japan and Australia—led by Assistant Professor Kazutoshi Sato from Kitami Institute of Technology and Associate Professor Jun Inoue from the National Institute of Polar Research in Japan—has focused efforts on understanding how fluctuations in these climatic factors affect the warming of the Antarctic. They have documented their findings in a brand-new article published in Nature Communications.

Previous studies have examined the relationship between the wind dynamics over the Southern Ocean (also called SO; located north of Antarctica) and climate variability in tropical oceans. It was found that heating in tropical regions generates atmospheric waves called “Rossby wave trains” from the tropics to the Antarctic region via the SO, which causes heating of the West Antarctic region. Interestingly, Rossby waves are an attempt of nature to balance heat in the atmosphere as they transfer heat from the tropics to the poles and cold air towards the tropics.

On the path of understanding the warming of AP, Dr. Sato points out, “The impacts of climate variabilities over the mid-latitudes of the Southern Hemisphere on this Antarctic warming have yet to be quantified”. His team addressed this gap by looking at the climate changes in the Tasman Sea located between Australia and New Zealand and the SO and drew correlations with temperature variations in the AP.

Dr. Sato and his team analyzed the temperature data from six stations in AP and the wind and cyclone patterns over the Tasman sea and the SO from 1979 to 2019. They found that even without unusual heating in the tropics, only the heating in the Tasman Sea modifies the wind patterns over the SO and forces the Rossby waves to move even deeper into the Amundsen sea low, a low-pressure area lying to the west of the AP. This larger pressure gradient causes stronger colder winds towards the poles. The meandering wind stream moves towards the AP, resulting in the warming of this region. Additionally, this effect was found to be prominent in the winter months when the cyclones are more active. “We have shown that warm winter episodes in the Tasman Sea influence warm temperature anomalies over key regions of West Antarctica, including the AP, through a poleward shift of South Pacific cyclone tracks”, Dr. Sato summarizes.

The ever-increasing warming of the AP—rather, the whole of Antarctica at large—is a major concern plaguing climatologists all over the world. Commenting on the serious implications of this rapid rise in temperature and sea levels and the importance of the findings of their study, Dr. Inoue says, “Antarctic warming accelerates Antarctic ice sheet melting and contributes to the rise in sea levels across the world. Therefore, knowledge of the mechanisms of the melting of the Antarctic ice sheet would help scientists, policymakers, and administrations to devise measures for people who will be most affected by the rising sea levels.”

Dr. Sato and his team conclude by stating that the findings of their study can also aid the future forecast of ice sheet melting in Antarctica and the consequent global sea level rise.


Read the original story here.
Cover photo by Phillip Capper / Wikimedia Commons.
Weakening Gulf Stream may disrupt world weather

Weakening Gulf Stream may disrupt world weather

By Tim Radford

The Gulf Stream is growing feebler, the Arctic seas are gaining fresh water. Together they could affect the world’s weather.

LONDON, 2 March, 2021 − The Atlantic Conveyer, otherwise the Gulf Stream − that great flow of surface water pouring northwards that overturns in the Arctic and heads south again at great depth − is now weaker than at any point in the last 1,000 years, European scientists report.

And in a second, separate but related study, researchers have found that the Beaufort Sea, in the Arctic, has gained two-fifths more fresh water in the last 20 years: water that could flow into the Atlantic to affect the Conveyor, and with it, climatic conditions.

Scientists call it the Atlantic Meridional Overturning Circulation or just AMOC. Europeans know it as the Gulf Stream: the current that conveys tropic warmth to their coasts and keeps Britain and Western Europe at a temperature several degrees higher than latitude alone might dictate.

And for years, oceanographers and climate scientists have been observing a slowing of the flow, by as much as 15%. But direct measurement of the great current began only relatively recently in 2004: researchers needed to know whether the slowdown was part of a natural cycle, or a consequence of climate change driven by global heating.

Now they know a little more. European researchers report in Nature Geoscience that they looked for evidence of ocean circulation shifts in what they call “proxy evidence”: the story of climate change told by tree growth rings, ice cores, ocean sediments, corals and historical records, including naval logbooks.

The combined evidence of temperature patterns, the sizes of particles of ocean floor sediment and the salinity and density of sub-surface water helps build up a picture of the Atlantic current for the last 1,600 years.

“The Gulf Stream System moves nearly 20 million cubic meters of water per second, almost a hundred times the Amazon flow”

The verdict? Up to the 19th century, ocean currents were stable. The flow is now more sluggish than at any time in the last millennium.

This is roughly what climate models have predicted: the warm salty water moves north, cools, becomes more dense, sinks to the deep and flows back south. But the Arctic has begun to warm, Greenland to melt, and the flow of fresh water into the northern seas to intensify.

Since the flow is driven by the difference in temperatures, any change in the regional thermometer will play back into the rate of flow. And any extra arrival of fresh water could further slow the overturning circulation.

“The Gulf Stream system works like a giant conveyor belt, carrying warm surface water from the equator up north, and sending cold, low-salinity deep water back down south. It moves nearly 20 million cubic meters of water per second, almost a hundred times the Amazon flow,” said Stefan Rahmstorf, of the Potsdam Institute for Climate Impact Research, in Germany, one of the authors.

“For the first time, we have combined a range of previous studies and found they provide a consistent picture of the AMOC evolution over the past 1600 years. The study results suggest that it has been relatively stable until the late 19th century.

“With the end of the Little Ice Age in about 1850, the ocean currents began to decline, with a second, more drastic decline following since the mid-20th century.”

Outcome awaited

The change could have ominous consequences for European weather systems: it could also deliver more intense coastal flooding to the US eastern seaboard. If the current continues to weaken, the consequences could be catastrophic.

Which is why a new study in Nature Communications matters so much. US researchers tracked the flow of fresh water from the Beaufort Sea − melt water from glaciers, rivers and disappearing Arctic sea ice − through the Canadian Archipelago and into the Labrador Sea.

Arctic water is fresher than Atlantic water, and richer in nutrients. But this extra volume, measured at a total of 23,300 cubic kilometres, could also affect the rate of flow of the overturning circulation. That is because relatively fresh water is less dense than saline water, and tends to float on top.

Quite what role it could play is uncertain: the message is that, sooner or later, it will escape into the North Atlantic. Then the world will find out.

“People have already spent a lot of time studying why the Beaufort Sea fresh water has gotten so high in the past few decades,” said Jiaxu Zhang,  of the Los Alamos National Laboratory, first author. “But they rarely care where the freshwater goes, and we think that’s a much more important problem.” − Climate News Network


This article was originally posted on the Climate News Network.
Cover photo by Michael Studinger, NASA (public domain), via Wikimedia Commons
UN survival plan offers new hope for the planet

UN survival plan offers new hope for the planet

By Tim Radford

A bold UN survival plan could put nature back in charge of the Earth − and researchers explain why that should happen.

LONDON, 26 February, 2021 − UN chiefs want to transform the world by putting nature back at the heart of global decision-making, arguing that the global economic shutdown triggered by the Covid-19 pandemic is an opportunity to change the planet for the better: for a stable climate, for cleaner air and water, and for a richer natural environment, thanks to the UN survival plan.

The goal? A more sustainable and more equitable world by 2030, a carbon-neutral world by 2050, a curb on global pollution and waste and a halt to ever-accelerating rates of wildlife extinction worldwide.

The methods? One of the first, in Making Peace With Nature, the new United Nations Environment Programme report, will be to incorporate what conservationists call “natural capital” into measures of national economic performance.

That is because forests, savannahs, wetlands and other natural habitats represent wealth, and their loss accelerates poverty. If nations and regions can reverse environmental decline then they can at the same time advance the alleviation of poverty, and secure reliable food and water, and good health, for all.

And to reinforce such arguments, new and entirely separate research continues to underline the UN vision of natural capital as real investment in the services on which all humankind depends.

Vital sanitation need

In 48 cities around the globe, nature provides at least 18% of the sanitation services: creatures in the soils filter and clean around 2.2 million cubic metres of human excrement in the form of pit latrines before it can reach the groundwater table.

Since, in 2017, around one fourth of the global population had no access to sanitation facilities, and 14% used toilets that disposed of waste on site, this is not just an important service but a vital one: vital to human health.

The same research team reports in the journal One Earth that − since more than 892 million people worldwide in effect release excrement into holes in the ground − then nature must sanitise more than 41 million tonnes of human waste every year before it gets into the groundwater. So that’s a service worth US$4.4 billion (£3.14bn) a year, British researchers calculate.

Around 70% of the world’s crops depend on insect pollination, and the range and abundance of insect pollinators is vulnerable to shifts in climate. Importantly, many crops rely on wild pollinators − that is, commercial honey bee colonies cannot always do the trick of turning flowers into fruit, or grain − so what happens to wild insect populations affects what is available for supper.

“The war on nature has left the planet broken. But it guides us by providing a peace plan and a post-war rebuilding programme”

US researchers report in the journal Ecological Applications that they took the case of wild bees and open field tomato crops: these depend on insects that release pollen by vibration, among them bumble bees.

They matched distribution of 15 species and climate data now against predictions for climate change across North America to find that − in the eastern US alone − within the next three to four decades, 11 species of pollinator could be in decline. The implications for food security are inescapable.

And a third study simply looked at what climate change, human population expansion, pollution and demand for freshwater had done to the planet’s rivers and lakes.

French and Chinese scientists report in the journal Science that they had identified what they call “marked changes” in the biodiversity of more than half the world’s rivers and lakes, thanks to human impact.

Of more than 1,000 fish species, 170 were extinct in their natural river basins, at a very conservative estimate. Out of 2,456 river basins, found everywhere except the deserts and the poles, 1,296 of them, covering more than 40% of the planet’s continental surface, and accounting for 37% of the length of the world’s rivers, revealed “deep and spatially distributed anthropogenic impacts.” That is science-speak for loss and defilement.

Lethal heat prospect

Such research − published on an almost daily basis − provides the context in which the latest UNEP report makes its argument. The report identifies a threefold planetary emergency and calls for advances in science and bold policy-making to make lives better both for the poorest in the world, and for nature itself.

It warns that the planet is heading for a warming of at least 3°C by the century’s end; that more than one million species could be heading for extinction; and that pollution-triggered diseases right now deliver an estimated nine million premature deaths each year.

“The war on nature has left the planet broken. But it also guides us to a safe place by providing a peace plan and a post-war rebuilding programme,” says António Guterres, UN secretary general, in the report’s foreword.

“By transforming how we view nature, we can recognise its true value. By reflecting this value in policies, plans and economic systems, we can channel investments into activities that restore nature and are rewarded for it.

“By recognising nature as an indispensable ally, we can unleash human ingenuity in the service of sustainability and secure our own health and well-being alongside that of the planet.” − Climate News Network


Cover photo by Dustan Woodhouse on Unsplash.
This article was originally posted on The Climate News Network.
Millions will die if world fails on climate promises

Millions will die if world fails on climate promises

By Tim Radford

Action to keep climate promises could prevent millions of deaths each year. Unless nations try harder, that won’t happen.

LONDON, 16 February, 2021 − Scientists have looked at conditions in just nine of the world’s 200 nations and found that − if the world keeps its Paris climate promises, of containing global heating to “well below” 2°C by 2100 − millions of lives could be saved.

And another team has looked at what nations actually propose to do so far to hit the Paris targets and found that it is not enough: that everybody will have to be 80% more ambitious.

But, though costly, such ambitions would deliver direct rewards. For a start, the consequences of embarking on policies that would seriously reduce the greenhouse gas emissions that fuel potentially catastrophic climate change could lead to better diets in Brazil, China, Germany, India, Indonesia, Nigeria, South Africa, the UK and the US: that alone could save 6.1 million lives.

Thanks to the cleaner air that would come with a drastic reduction in fossil fuel combustion, another 1.6 million people could expect to breathe freely for another year. And the shift from private cars to public transport and foot or bicycle journeys would mean another 2.1 million of us could expect to go on benefiting from the additional exercise for another year, every year.

The Lancet Countdown on Health and Climate Change says in the journal Lancet Planetary Health that it selected the nine nations because they embraced around half the global population and accounted for seven-tenths of the world’s greenhouse gas emissions.

“The message is stark. Not only does delivering on Paris prevent millions dying prematurely each year; the quality of life for millions more will be improved through better health”

The Countdown also looked at a range of scenarios for action. And the researchers also considered what, so far, those nine nations had promised to do to contain climate change − the international bureaucratic language calls such promises nationally determined contributions, or NDCs − and found them far short of the effective target: right now, the world is heading for a global temperature rise by 2100 of 3°C or more.

And with these higher global average temperatures there will be more devastating and possibly lethal heat waves, more intense and more frequent storms, protracted drought, torrential rain and flooding, and rising sea levels that will intensify erosion and coastal flooding.

The damage that these threaten alone delivers a long-term economic case for concerted global action to shift agricultural emphasis, save natural ecosystems and switch to renewable fuel sources. But the right choice of action could make lives a great deal better as well.

“The message is stark,” said Ian Hamilton, executive director of the Lancet Countdown. “Not only does delivering on Paris prevent millions dying prematurely each year; the quality of life for millions more will be improved through better health. We have an opportunity now to place health in the forefront of climate change policies to save even more lives.”

On the same day, a US team published the results of a look at what nations had to do to actually meet the goal chosen at a global conference in Paris in 2015 to contain global heating to no more than 2°C above what had been the long-term average for most of human history.

Avoiding despair

In the last century alone the planet has warmed by more than 1°C, and the last six years have been the warmest six years since records began. The promises made in Paris, if kept, could mean a 1% drop in greenhouse gas emissions every year.

But, scientists say in the journal Communications Earth and Environment, that will not contain global heating to 2°C. To deliver on the promise, the world must reduce emissions by 1.8% a year. That is, the global community will have to try 80% harder.

Some nations are nearer the more ambitious target: China’s declared plans so far would require only a 7% boost. The UK would have to raise its game by 17%. The US − which abandoned the Paris Agreement under former President Trump − has 38% more work to do.

“If you say ‘Everything’s a disaster and we need to radically overhaul society’ there’s a feeling of hopelessness,” said Adrian Raftery of the University of Washington, one of the authors.

“But if we say ‘We need to reduce emissions by 1.8% a year’ that’s a different mindset.” − Climate News Network


This article was originally posted on The Climate News Network.
Cover photo by Maverick Photo Agency, via ClimateVisuals