Category: Water

Drought may hit half world’s wheat at once

Drought may hit half world’s wheat at once

By Tim Radford

The planet’s daily bread could be at risk as the global thermometer creeps up and climates begin to change. New research has warned that almost two thirds of the world’s wheat-growing areas could face “severe, prolonged, and near-simultaneous droughts” by the century’s end.

Right now, 15% of the world’s wheat producing regions are at risk of severe water scarcity at the same time. Even if the 195 nations that agreed in Paris to stop global average temperatures from rising beyond 1.5°C by 2100 keep that promise, the chance of simultaneous water stress across continents would still double between 2030 and 2070.

But if nations fail to mitigate the climate change and extremes of heat and rainfall that would inevitably follow runaway global heating, then the chances of devastating failure of wheat harvests in both Europe and North America, or both Europe and Australia, or Russia, Ukraine and Kazakhstan, begin to soar.

Wheat provides one-fifth of all the calories for humankind. It is the world’s largest rain-fed crop and the global wheat trade matches the traffic in rice and in maize combined. Ten regions account for 54% of the planet’s wheat fields, and 57% of the world’s wheat.

“The results indicate a severely heightened risk of high-impact extreme events under the future climate”

Scientists from Europe, the US and China report in the journal Science Advances that they worked with computer simulations to model the future global weather for water scarcity with changes in temperature for the next eight decades.

Wheat is a successful crop partly because its water needs are relatively low, but it can’t flourish without reliable rainfall before and during growth. And the new simulations confirm earlier fears: that extremes of heat and devastating drought could happen in more than one continent at the same time.

When this happened in the 19th century, global famine followed. Forecasts already warn that with each 1°C rise in temperature, global wheat yield will fall by between 4% and 6.5%. Researchers have repeatedly warned that extremes of heat can slash yields and limit the vital nutrients in cereal harvests. Other teams have found that climate change may already be making this happen.

Worse could follow as one heat wave is pursued promptly by another. And all this could happen in a world in which, as population grows, demand for wheat could increase by at least 43%.

Continued checking

Scientists tend not to take the research of others for granted: they keep on checking. The latest simulation analysed 27 different climate models, each with three different scenarios.

The scientists looked at evidence from the near-past to find that between 1985 and 2007, the impact of drought on world wheat production was twice that between 1964 and 1984.

They included developing countries and low-income nations in eastern and southern Asia in their survey, because these are where half of the already hungry and under-nourished live, and where bread is an important part of people’s diet.

“The results indicate a severely heightened risk of high-impact extreme events under the future climate, which would likely affect all market players, ranging from direct influences on subsistence farmers to price-mediated changes in international markets”, they write.


The article was originally published on The Climate News Network.
Cover photo by Melissa Askew on Unsplash.
The Impact of Global Warming on Water

The Impact of Global Warming on Water

By Mark Barber

While politicians and laypeople debate whether global warming is real, the effects of climate change continue to steadily creep into every ecosystem on the planet—and that has major consequences for life as we know it.

One of the most concrete ways to grasp the impact of climate change is to understand how global warming affects water around the world. As you’ll see, global warming’s effects are intersectional. The impacts of climate change on water, for example, have repercussions for agriculture, drinking water, weather, power supplies, wildlife, and more. Thus, examining climate change through the lens of water helps shed light on its far-reaching effects.

We’ll be honest: Learning about climate change can be disheartening. But it’s important not to let the following information lead to disempowerment. Instead, consider this information a call to action on behalf of our water and our planet.

The Impact of Global Warming on Water

How Global Warming Affects Water

Here are just some of the ways global warming affects water around the world.

Precipitation pattern shifts
One of the most well-documented effects of climate change is its impact on the water cycle—especially precipitation. Scientists forecast that climate change will provoke new and less predictable precipitation patterns, dubbed “drought and deluge” or “precipitation whiplash.”

As these terms imply, it’s likely that precipitation patterns will consist of prolonged periods of dryness punctuated by brief, intense periods of precipitation that may provoke flooding. The risk of flooding is higher if it’s preceded by drought.

Climate change may cause more droughts because rising air temperatures lead to higher rates of evaporation and plant transpiration, thereby speeding up water loss from the soil and plants. This process may help account for the California droughts of 2011 and 2017 and the 2012 to 2013 drought that impacted much of North America.

Meanwhile, climate change is also making extreme precipitation events more likely. Studies suggest climate change may have provoked the massive amount of rainfall and flooding—and subsequent devastation—that occurred during 2018’s Hurricane Florence in North Carolina and 2017’s Hurricane Harvey in Texas. Flooding also poses a major threat to low-lying agricultural areas such as the Netherlands’ Flevoland.

Extreme precipitation events can bring devastating consequences in the form of ecological harm, property damage and loss, massive financial costs, and even death of people and animals. A recent study by The National Oceanic and Atmospheric Administration (NOAA) discovered that since 1980, many of the most economically disastrous weather- and climate-related disasters were related to water. For instance, tropical cyclones, droughts, severe storms, and flooding have resulted in costs totaling roughly $927 billion, $247 billion, $232 billion, and $124 billion, respectively.

the economic cost of weather and climate related disasters

How do my hydration needs compare to yours?

The Chesapeake Bay Watershed on the United States’ mid-Atlantic coast is another living example of many of the impacts brought on by extreme weather events. Between 1958 and 2012, the northeastern U.S. reportedly experienced a more than 70 percent increase in the amount of rainfall measured during heavy precipitation events. This has led to flooding, an increase in pollution running off into the bay, and changes in the water’s salinity (which impacts the ability of aquatic animals and flora to survive).

Diminished water quality
Global warming can impair water quality in several ways, which can have significant consequences for people, wildlife, and ecosystems. Take, for instance, these situations.

  • As noted above, climate change is leading to more intense precipitation events. Intensified precipitation levels lead to increased runoff. This runoff carries with it pesticides, herbicides, and other agricultural chemicals and disease pathogens—all of which end up in the waterways that supply humans, wildlife, and plant life with water. Increased pollution levels in waterways also lead to a rise of algal blooms, which we’ll address below.
  • Climate change is causing air temperature to rise, which provokes corresponding water temperature increases in lakes, reservoirs, and streams. Higher water temperatures are associated with reduced levels of dissolved oxygen in bodies of water. Lower oxygen levels place significant stress on aquatic animals—including crustaceans, fish, and insects—which need oxygen to survive.

The U.K. serves as an example of how climate change can impair water quality. Across this region, floods and droughts are on the rise. As noted above, flooding can negatively impact water quality in several ways, from increased pollution levels to more frequent or intense algal blooms.

Algal blooms
As noted above, algal blooms—or overgrowths of algae in bodies of water—can occur as a result of increased pollution in waterways (most notably pollution from nitrogen and phosphorous). A 2018 report from the Environmental Working Group (EWG) found that algal blooms are becoming more common and more intense, and that’s bad news for our waterways and our health.

Some of these blooms produce harmful toxins that may be fatal to people and animals. Even blooms that don’t produce toxins can be harmful to the environment and local economies in several ways.

  • They may produce “dead zones” in the water where aquatic animals and flora cannot survive.
  • They make it harder to produce clean drinking water, thereby raising the treatment costs associated with obtaining safe drinking water.
  • They harm any industry or recreational activity that relies on clean water.

Again, the Chesapeake Bay Watershed offers a case study: Rising temperatures in the summer have contributed to algal blooms that have created “dead zones” and resulted in the widespread die-off of fish, other marine life, and underwater grass beds—impacting both the ecosystem and the local economy.

Why does climate change provoke algal blooms? Scientists studying algal bloom growth across the U.S. suspect a number of factors including the following:

  • Warmer water temperatures, which create an appealing environment for algal growth
  • Changes in salinity, which make it easier for marine algae to infiltrate freshwater ecosystems
  • Higher carbon dioxide levels, which feed algal growth
  • Extreme precipitation events, which can lead to runoff containing chemicals that feed algal growth
  • Sea level rise, which is expected to produce more shallow, stable pools of coastal water with conditions ideal for algal growth

Fjords in Scandinavia represent what can happen when these climate-change-induced shifts affect waterways. Nutrient pollution that spurs the growth of potentially harmful bacteria impact waterways and make it harder for native aquatic species to survive. Protecting the fjords is of utmost importance, because research suggests fjords play a big role in absorbing carbon and reducing atmospheric levels of carbon dioxide (a major contributor to climate change).

Declines in drinking water
If you’ve read this far, then it probably comes as no surprise that climate change is diminishing both the quality and the quantity of drinking water. This may occur for a number of reasons including the following:

  • Algal blooms make it harder to treat water and may emit toxins or cause plant and aquatic wildlife die-offs that significantly diminish water quality.
  • Higher temperatures may reduce the availability of drinking water by provoking the loss of mountain glaciers and mountain snowpack, and causing earlier spring snowmelts—all of which reduces the amount of available water in streams, rivers, and other bodies of water. Melting glaciers alone are expected to threaten the drinking water supply for millions of people.
  • Rising sea levels may carry saltwater to groundwater drinking supplies, making it harder to convert that groundwater (especially in low-lying, coastal regions) into drinking water.
  • Extreme precipitation events are likely to increase the presence of pollution in waterways, which can make it more difficult to treat drinking water. These events may also provoke the overflow of municipal sewer systems, which could release untreated sewage into local drinking water supplies.

The glaciers in the Alps represent the direness of the situation. New research has found that unless climate change slows or halts, two-thirds of the ice in the Alps glaciers is expected to melt by the end of the century, with half of that ice melting by 2050. This melting is expected to have a massive impact on water availability for drinking, farming, generating electricity, and more.

Other extreme examples of the decline in available water can be found in southern Spain, which is expected to completely convert to desert by the end of the century unless climate change is halted, and in parts of Australia, where desertification is also increasing.

Disruptions to power supplies
Climate change not only directly impacts water supplies for humans, wildlife, and ecosystems, but it may also disrupt human power supplies, as evidenced by the following:

  • Currently, glaciers supply many power plants around the world. As glaciers melt, available power supplies may also shrink.
  • Higher temperatures may decrease the water present in lakes and rivers, thereby limiting the abilities for hydroelectric plants to function at capacity—or at all.
  • Higher temperatures may also make available water sources too warm to effectively cool coal and nuclear power plants. This may cause what’s referred to as “power brownouts,” or drops in voltage within an electrical power supply system.

In a catch-22, power may become less available at a time when energy is more needed than ever to treat and distribute declining water supplies. All of this speaks to the immediate and pressing need to switch to renewable, less-resource-intensive energy sources.

Stronger hurricanes
Climate change has been linked to some of the strongest hurricanes to affect the U.S. in recent years. Research suggests these aren’t isolated incidents; instead, hurricanes and tropical cyclones are expected to get stronger if climate change escalates. This is true for multiple reasons including these.

  • Rainfall rates associated with tropical cyclones are expected to increase, because rising air temperature causes a rise in moisture content in the atmosphere. This means more moisture is likely to fall during storm events.
  • Rising sea levels create higher storm surge levels for tropical cyclones, which can exacerbate the damage caused by these storms.
  • While tropical cyclones capable of reaching maximum intensity used to be isolated to a relatively narrow geographic region, research suggests this region is expanding, meaning intense tropical cyclone activity may occur in more places around the globe. All told, climate scientists predict the number of tropical cyclones reaching very intense categories (Category 4 or 5) will increase over the course of the 21st century.

Heat waves
Heat waves have already become more common across numerous regions throughout the world, and the top 20 warmest years on record have all occurred since 1995. Meanwhile, computer models predict that average temperatures around the globe will rise anywhere from 3.2 to 7.2 degrees Fahrenheit over the course of the 21st century. These heat waves exacerbate many of the water-related effects of climate change, including droughts, algal blooms, and rising sea levels.

5 small but mighty changes to affect climate change

Conclusion

While this list represents some of the most significant impacts of global warming on water, it is far from exhaustive. Climate change is also likely to impact water’s role in agriculture, ocean circulation, recreation, and many other areas.

It’s important to note, however, that all hope is not lost. Climate change can still be slowed by taking dramatic steps to reduce greenhouse gas emissions, such as transitioning to renewable energy sources or scaling back the industrial dairy and meat industries. We can all encourage these processes by urging local, state, and federal governments to invest in renewable energy and reducing our dairy and meat consumption. It’s not too late for each one of us to make a difference and help slow climate change’s impact on our precious water resources.


Cover photo and article by Waterlogic, presented with permission.
Balkan water reserves may soon run short

Balkan water reserves may soon run short

By Kieran Cooke

The Balkans is one of the world’s most troubled regions, often the setting for outbreaks of territorial, ethnic and religious conflict.

Now the area is also having to face up to the problems caused by a changing climate – in particular the prospect of severe water shortages in the years ahead.

Albania, a mountainous country with a population of just under 3 million, has abundant water resources at present. But government studies predict that due to increasing temperatures and declining rainfall, there could be severe water shortages within ten years.

The government says that within a decade water levels in three of the country’s biggest rivers – the Drin, Mat and Vjosa – will be up to 20% lower than at present.

Albania, largely isolated from the outside world for much of the second half of the 20th century under the Stalinist regime of Enver Hoxha, is struggling to build its economy, with hopes of joining the European Union in the not too distant future.

“Kosovo, Montenegro and North Macedonia all depend on coal for a substantial segment of their power generation”

Falling water levels in its rivers could seriously impede economic progress. More than 80% of Albania’s power is derived from hydro. Even a slight drop in water levels in the nation’s rivers results in power black-outs.

In the summer of 2017 Albania suffered a widespread drought; it was forced to use precious foreign currency reserves for power imports.

Added to these problems is a chronic lack of investment in water infrastructure and mismanagement in the sector. The country has more than 600 dams, but 70% of these are believed to be in need of repair; estimates are that up to half the total water supply is lost in leaks.

In recent years rainfall patterns have become less predictable – with sudden storms causing extensive flooding. Deforestation and haphazard building development along Albania’s water courses result in rivers frequently bursting their banks.

Rivers and water resources, like climate change, do not obey borders. Albania is dependent for a third of its water on neighbouring countries.

Slow progress

The waters of the Drin, Albania’s major river, are shared with the newly independent states of Kosovo and Montenegro in the north and with North Macedonia in the east. Territory in northern Greece also forms part of the Drin river basin. The area is one of the most ecologically rich in Europe.

After many years of territorial, ethnic and religious conflict, efforts are now being made to manage the waters of the Drin on a cross-boundary basis, though progress is often painfully slow.

Ironically, some countries in the region are contributing to their own climate change problems. Kosovo, Montenegro and North Macedonia all depend on coal for a substantial segment of their power generation.

Coal-fired power plants are among the leading sources of climate-changing greenhouse gases. Lignite coal – the most polluting variety of the fuel – is mainly used in the western Balkans region. The small state of Kosovo has some of the largest lignite reserves in the world.

Due primarily to the burning of lignite at ageing power plants, air pollution is a big problem in the country. Pristina, the capital, is often blanketed in a thick black haze in the winter months and regularly tops the world league of cities with the worst air quality.


This article was originally published on The Climate News Network.
Cover photo by on Elti Meshau on Unsplash.
ADB supports Marawi reconstruction with stakeholder dialogues for water supply rehabilitation

ADB supports Marawi reconstruction with stakeholder dialogues for water supply rehabilitation

By Joy Amor Bailey

The ADB Southeast Asia Regional Department (SERD) held a mission in Marawi City, Philippines on 26–28 February to refine the scope of activities under Output 3 of the $408 million Emergency Assistance for Reconstruction and Recovery of Marawi project. 

This includes a $5 million grant from the Urban Climate Change Resilience Trust Fund (UCCRTF), which will be allocated for the health and water supply components of the project.  

The mission focused on identifying and selecting a site for the water supply rehabilitation, as well as conducting social and environmental safeguards, determining procurement of goods and services, and ensuring delivery timelines.  

During the mission, the guidance note, “A Resilience Framework for the Post-conflict Reconstruction of Marawi and Other Affected Areas”, was presented. The note is intended for Task Force Bangon Marawi (TFBM) and partner implementers to integrate peace-building, disaster risk management, and climate change adaptation principles in the post-conflict recovery process.  

Through an interactive half-day workshop, the stakeholders were briefed on technical guidelines for priority sectors. This resilience framework is expected to inform ADB’s overall support and also help guide other activities of the TFBM for project vetting and monitoring. 


Cover photo by Xiaolong Wong on Unsplash.
This article was originally published on the Livable Cities ADB Blog.

Civil works for RISE demonstration site underway

Civil works for RISE demonstration site underway

By Joy Amor Bailey

Civil works at the demonstration site for the Revitalization of Informal Settlements and their Environments (RISE) using a Water-sensitive Approach in Makassar, Indonesia are underway and due for completion by June 2019. The works use decentralized, green infrastructure to treat contaminated and polluted water. 

Using community-driven development approaches, the RISE project is empowering urban poor beneficiaries to co-design and implement nature-based solutions for sanitation, drainage, and water supply. These form part of their climate change adaptation response, as well as enhances the health and environmental conditions of the community.  

RISE-demonstration-fig1.jpg
Ongoing installation of nature-based solutions for the RISE Project. 

The Urban Sector Group under the Sustainable Development and Climate Change Department of the Asian Development Bank (ADB) is implementing this pilot project with funding from the Urban Climate Change Resilience Trust Fund amounting to $196,000. Monash University is co-implementing the project, providing $93,000 for the equipment and civil works.  

The City Government of Makassar has also pledged to finance the construction and maintenance of other amenities such as street lighting and solid waste management, as well as the subsidies of up to $1,000 per housing unit to improve its structural integrity and reduce household vulnerability. 

In addition, ADB’s Southeast Asia Department, together with Indonesia’s Ministry of Public Works and Housing, is currently preparing an investment grant that will replicate this project in additional sites. 


This article was originally published on ADB’s Livable Cities Blog.
Cover photo by Casey Schackow on Unsplash.
Glaciers’ global melt may leave Alps bare

Glaciers’ global melt may leave Alps bare

By Tim Radford

Many of the planet’s most scenic – and most valued – high-altitude landscapes are likely to look quite different within the next 80 years: the glaciers’ global melt will have left just bare rock.

By the century’s end, Europe’s famous Alps – the chain of snow- and ice-covered peaks that have become a playground of the wealthy and a source of income and pleasure for generations – will have lost more than nine-tenths of all its glacier ice.

And in the last 50 years, the world’s glaciers – in Asia, the Americas, Europe, Africa and the sub-Arctic mountains – have lost more than nine trillion tonnes of ice as global temperatures creep ever upwards in response to profligate combustion of fossil fuels.

And as meltwater has trickled down the mountains, the seas have risen by 27mm, thanks entirely to glacial retreat.

“Present mass-loss rates indicate that glaciers could almost disappear in some mountain ranges in this century”

In two separate studies, Swiss scientists have tried to audit a profit and loss account for the world’s frozen high-altitude rivers, and found a steady downhill trend.

Glacial ice is a source of security and even wealth: in the poorest regions the annual summer melt of winter snow and ice banked at altitude can guarantee both energy as hydropower and water for crops in the valleys and floodplains.

In wealthy regions, the white peaks and slopes become sources of income as tourist attractions and centres for winter sport – as well as reliable sources of power and water.

Swiss focus

In the journal The Cryosphere, a team from the Swiss Federal Institute of Technology, almost always known simply as ETH Zurich, looked into the future of the nation’s own landscape, and beyond.

They made computer models of the annual flow of ice and its melting patterns and took 2017 as the reference year: a year when the Alpine glaciers bore 100 cubic kilometres of ice. And then they started simulating the future.

If humankind kept the promise made by 195 nations in Paris in 2015, to drastically reduce fossil fuel use, lower emissions of carbon dioxide, restore the forests and keep global warming to no more than 2°C above historic levels, then the stores of high ice would be reduced by more than a third over the next eight decades. If humankind went on expanding its use of fossil fuels at the present rates, then half of all the ice would be lost by 2050 and 95% by 2100.

Time lag

But there will be losses in all scenarios: warming so far has seen to that. Ice reflects radiation and keeps itself cold, so change lags behind atmospheric temperature.

“The future evolution of glaciers will strongly depend on how the climate will evolve,” said Harry Zekollari, once of ETH and now at Delft University of Technology in the Netherlands, who led the research. “In the case of a more limited warming, a far more substantial part of the glaciers could be saved.”

The Alpine glaciers were made world-famous first by Romantic painters and poets of the 19th century, among them JMW Turner and Lord Byron. But their contribution to rising sea levels is, in a global context, negligible.

When Swiss researchers and their Russian, Canadian and European partners looked at the big picture, they found that the mass loss of ice from the mountains of Alaska,  Canada, parts of Asia and the Andes matched the increasing flow of water from the melting Greenland ice cap, and exceeded the flow of melting water from the Antarctic continent.

Europe’s modest melt

They report in Nature that glaciers separate from the Greenland and Antarctic sheets covered 706,000 square kilometres of the planet, with a total volume of 170,000 cubic kilometres, or 40 centimetres of potential sea level rise.

And in the five decades from 1961 to 2016, according to careful study of satellite imagery and historic observations, the seas have already risen by 27mm as a consequence of increasing rates of glacial retreat. This is already between 25% and 30% of observed sea level rise so far.

Europe did not figure much in the reckoning. “Globally, we lose three times the ice volume stored in the entirety of the European Alps – every single year,” said Michael Zemp, a glaciologist at the University of Zurich.

He and his colleagues warn: “Present mass-loss rates indicate that glaciers could almost disappear in some mountain ranges in this century, while heavily glacierised regions will continue to contribute to sea level rise beyond 2100.”


This article was originally posted on The Climate News Network and has been republished under Creative Commons.
Cover photo by Karl Koehler on Unsplash.
This New Climate Episode 2: Running dry – dealing with water scarcity

This New Climate Episode 2: Running dry – dealing with water scarcity

This month has been all about water and how climate change will have an affect on different aspects of it. Today we bring you an episode from our latest podcast series, This New Climate.

In the second episode of This New Climate, host Will Bugler explores why it is so difficult to manage water resources and presents Water2Invest – a new tool that helps decision makers make smarter choices about managing water supply and demand. The world’s population has tripled over the last 100 years, but according to the UN, water demand has been growing at more than twice that rate making water scarcity one of the defining challenges of our time. And climate change will only compound the problem. Water2Invest, aims to help decision makers to take the right choices when investing in solutions to tackle water scarcity, potentially providing a powerful new tool to help tackle this crisis.

Episode guests: Gisela Kaiser from the City of Cape Town, Mark Bierkens from Utrecht University, and Daniel Zimmer from EIT Climate-KIC.

This New Climate is an Acclimatise production.

Click here to access the full season.

Water2Invest is an EIT Climate-KIC supported innovation initiative.

New project supports climate adaptation and resilience for Pacific Islands

New project supports climate adaptation and resilience for Pacific Islands

By Will Bugler

Fifteen Pacific island countries are part of the newly launched Pacific Adaptation to Climate Change and Resilience Building (PACRES) project under the Intra-African Caribbean Pacific (ACP) Global Climate Change Alliance Plus (GCCA+) Programme funded by the 11th European Development Fund’s (EDF). The EUR 12 million project aims to strengthen adaptation and mitigation measures at the national and regional level and support partner countries in climate negotiations and in implementing the Paris Agreement on climate change.

Jointly implemented by the Secretariat of the Pacific Regional Environment Programme (SPREP), the Pacific Community, the Pacific Islands Forum Secretariat (PIFS) and the University of the South Pacific, the project will also have a disaster resilience component. Some of the activities of the project, according to SPREP, include knowledge sharing, strengthening of networks, and trainings and research opportunities.

An inception and planning meeting for the project was held from 1-3 April 2019 at the SPREP Campus in Samoa.

The Cook Islands, the Federated States of Micronesia (FSM), Fiji, Kiribati, Niue, Nauru, Palau, Papua New Guinea (PNG), the Marshall Islands, Samoa, Solomon Islands, Timor-Leste, Tonga, Tuvalu and Vanuatu participate in the project.


Photo Credit: Gemma Longman

Ocean productivity at risk as climate warms

Ocean productivity at risk as climate warms

By Tim Radford

Runaway climate change will alter the pattern of ocean productivity and circulation and play perhaps irreversible havoc with fish catches.

LGlobal ocean productivity – the annual bloom of algae and the cornucopia of molluscs, shrimp, krill, squid, fish and marine mammals that depend on this flowering of the blue planet – could be in serious decline by 2300,  thanks to climate change.

The harvest from the North Atlantic could fall by almost two thirds. The decline in the Western Pacific could drop by 50%. The overall productivity of the oceans from pole to pole will be at least 20% less.

Global warming that is already melting the ice caps and increasingly making the seas more acidic has been blamed for changes in fishery hauls and damage to reef ecosystems.

But the latest study looks not at the immediate consequences of profligate human combustion of fossil fuels, but at the very long-term consequences of turning up the planetary thermometer.

Scientists report in the journal Science that three centuries of continuous rise in carbon dioxide levels in the planet’s atmosphere, as a consequence of fossil fuel combustion, could raise global average temperatures by 9.6°C.

This is ten times the warming already observed. It will change wind patterns, melt almost all the sea ice and increase ocean surface temperatures.

And with this increase in temperature comes change in the growth of phytoplankton, on which ultimately all marine life depends. There will be shifts in ocean circulation that will take nutrients from the surface and deposit them in the deepest waters.

Antarctic waters could become richer in nutrients. But the world’s human population is centred in the northern hemisphere. “Marine ecosystems everywhere to the north will be increasingly starved for nutrients, leading to less primary production by phytoplankton, which form the base of ocean food chains,” said Keith Moore, an earth system scientist at the University of California, Irvine, who led the study.

“By looking at the decline in fish food over time, we can estimate how much our total potential fisheries could be reduced.”

Research of this kind is based on computer simulation of an entire planetary ocean system over the next 280 years. Leaders from almost all the world’s nations vowed in Paris in 2015 to contain global warming, and other studies have shown that world commercial fisheries would benefit from such action.

Delayed response

But time is running out: the oceans have yet to respond fully to the greenhouse gases that have already built up in the atmosphere in the last century or so.

“The climate is warming rapidly now, but in the ocean, most of that added heat is still right at the surface. It takes centuries for that heat to work its way into the deeper ocean, changing the circulation and removing the sea ice, which is a big part of this process,” Dr Moore said.

“This is what’s going to happen if we don’t put the brakes on global warming, and it’s pretty catastrophic for the oceans.

“There is still time to avoid most of this warming and get to a stable climate by the end of this century, but in order to do that, we have to aggressively reduce our fossil fuel use and emissions of greenhouse gas pollutants.”


This article first appeared on the Climate News Network.

Photo by Lalo on Unsplash

Big storm clusters are on the increase – what this means for hurricane hotspots

Big storm clusters are on the increase – what this means for hurricane hotspots

By Anitha Karthik

Melting glaciers, rising sea levels, global warming and violent storms: the effects of climate change are well documented. But a growing weather trend that has caused much concern is storm clustering – when three (sometimes more) hurricanes or typhoons group together in a short space of time, gathering strength and unleashing even greater devastation.

The development of a tropical depression – a low pressure area with thunderstorms and winds below 39mph – to a tropical storm that attains hurricane strength in less than six hours, shows how quickly these things can intensify.

But increased frequency is also a trend, as storms follow each other in quick succession. Those who question the existence of climate change should look at the global hurricane history, or even the hurricane pattern in their own country. If we look at these storms, patterns of increasing intensity and frequency clearly demonstrate how climate change is having a direct impact on the way hurricanes behave.

In developed countries coastal residents in affected areas are keenly aware of these hazards and respond well during emergencies by liaising with local agencies and heading to designated shelters during evacuations. But this is not the case in developing and underdeveloped countries, although basic response awareness exists through devastating experience and a degree of public information.

Predicting the big ones

Thanks to advances in hurricane forecasting and hindcastingtechniques, situations like the Galveston hurricane in 1900, which struck the Texas coast without any official warnings, are happily a thing of the past.

The weather prediction models of the National Hurricane Center and the European Centre for Medium Range Weather Forecasting are able to plot the likelihood of impending hurricane paths – known as the “cone of uncertainty” – five days in advance, and are generally accurate.

But the real issue is how prepared we are around the world for the increasing frequency of hurricanes and their terrifying “gang” version, hurricane trios. This violent onslaught of hurricane-strength storms batters communities and destroys buildings and infrastructure from the US to the Caribbean to South-East Asia. But should communities on the coast stay and defend, or retreat altogether?

A deadly trio of hurricanes from 2018 heading across the Atlantic. NASA

Hurricane season

Hurricanes hammered the Atlantic from 2016 and 2018, including the Category 5 Matthew (2016), the Harvey-Irma-Maria trio (2017), which registered Category 4, 5 and 4 respectively, and Category 4 Florence and Michael (2018). This not only revealed the rising trend in intensity and frequency, but also alerted the world to the phenomena of clustering.

Critically, predicting the path of a hurricane depends on forecasting the dynamics of its intensity. Understanding the factors that contribute to the sudden changes in the strength (or weakening) of a hurricane is crucial. Changes in wind direction, interaction with the land at the coast, and ocean temperature and depth all play their part in altering the intensity of a hurricane that is highly sensitive to even slight changes.

In general, the accuracy of predicting the way a hurricane intensifies and then re-intensifies in less than 24 hours is more challenging than predicting its path. But these dynamics are the underlying factors which compound the threat of hurricane frequency. These dynamics are also capable of further altering storm surge characteristics by triggering coastal and inland flooding – such as abnormal rises in water levels – which often result in shocking devastation.

Hurricane Michael in 2018 was the perfect example of the importance of predicting how rapidly a hurricane has intensified before it hits the coast, in this case Florida. The predicted track of the storm was almost accurate but its intensity was more difficult to assess.

The National Hurricane Center forecasted Michael’s path by issuing a five-day cone of uncertainty advising of sustained winds of 65mph. However, the sudden change in the storm’s dynamics changed a Category 1 hurricane to a Category 4 with winds of 155mph. This underscores the uncertain and variable nature of hurricane prediction.

Hurricane Michael after it made landfall in the Florida panhandle. NASA

Building on sand

Despite these emerging and changing weather-related risks, residential and public buildings are still going up on affected coastal areas. Recent research in China identified a tsunami that swept away the present-day coastal province of Guangdong in 1076AD. It means storm-related surges have been documented in the region for more than 1,000 years – yet still building and expansion goes on heedless of the risk.

This is almost the same situation for all vulnerable coastal cities. For instance, Florida has hundreds of thousands of coastal residents living in Low Elevation Coastal Zones – land that is less than ten metres above sea level and within 200km of the coast – but yet again construction there continues despite the threat of hurricanes every season.

Developers are already conceiving storm-resilient buildings that can withstand winds of at least 200mph – a Category 5 hurricane. But it’s unlikely many have considered the compounded stress effect on structures having to continuously withstand hurricane force winds more frequently and in quick succession.

A mudslide in Ucab in the Philippines caused by Typhoon Manghut in September 2018. EPA

Building massive sea defences along vulnerable coastlines is practically impossible and isn’t a permanent solution to increasing coastal storm hazards. There is no point in risking lives by remaining, as storm clusters can be unpredictable. It is simply too dangerous, so evacuation is the only option. However, when it comes to coastal assets and investments, defending in a more appropriate and sensible way is required.

Some coastal cities are planning ahead. A recent development of extensive parks in Boston, US, aims to protect the urban shoreline infrastructure from flooding. And a 2009 studyrevealed the effectiveness of mangrove planting in coastal areas of India to protect the shoreline and reduce cyclone damage. But more practical solutions are needed, especially in more vulnerable developing regions, because cluster storms are not going away any time soon.


This article was originally published on The Conversation and was republished under Creative Commons Licensing.
Cover photo by NASA on Unsplash.