Category: europe

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
Rising heat affects Europe’s floods and droughts

Rising heat affects Europe’s floods and droughts

By Tim Radford

Patterns of Europe’s floods and droughts are starting to change: each could be more extreme, and far likelier with rising heat.

Climate change has begun to affect the pattern of Europe’s floods. The past three decades have seen “exceptional” flooding, say Austrian scientists who have worked their way through documentary records for the last 500 years.

At the same time, heat and drought affecting the continent are on the increase. The summer of 2018 broke all records for Germany, Austria and Switzerland, and by 2019 many trees in Europe’s forests were partly or entirely dead. And by 2085 rainfall could decline by a fifth, Swiss ecologists report, to alter the make-up of the forests dramatically.

Both findings are consistent with the big picture of climate change worldwide: wet seasons will become ever wetter; dry seasons too will become more extreme, according to US researchers in a third separate study.

All attempts to establish climate records involve careful interrogation of the past. Günter Blöschl of Vienna’s University of Technology and colleagues report in Nature that they sifted evidence from mountain lake beds, floodplains and 500 years of contemporary documents to identify decades more than usually rich in floods.

The floods of 1990 to 2016 in Western and Central Europe have been among the worst in history. To make sure of such a claim, the researchers identified periods of calamitous inundation across the whole region in the late 16th century and again in the 17th; and in the 18th and early 19th centuries.

“We should be preparing for the future by improving the technology to efficiently use water for crops”

If these episodes had anything in common, bygone floods happened when air temperatures were lower: fewer of them, too, happened in the summer.

“This finding seems to contradict the observation that, in some areas such as in the northwest of Europe, the recent warmer climate is aligned with larger floods,” Professor Blöschl said. “Our study shows for the first time that the underlying mechanisms have changed.

“While in the past floods have occurred more frequently under colder conditions, the opposite is the case now. The hydrological conditions of the present are very different from those in the past.”

Now, 55% of Central European floods happen in the summer, compared with 41% in previous centuries. It’s a message for planners, city chiefs and governments across the region: flood management is going to have to adapt.

So, too, is forest and woodland management, say scientists in Switzerland and Germany, who have been measuring changes in the canopies of their forests.

Growing vulnerability

For most of Europe, the single most extreme heatwave has been that of 2003: that is, until 2018. The sustained heat and aridity made temperatures in the growing season of 2018 on average 1.2°C higher than 2003, and 3.3°C higher than the average from 1961-1990.

Woodland foliage showed signs of drought stress. Leaves wilted, aged and dropped much earlier, and by 2019 many trees were dead, or partly dead. Those that survived were more vulnerable to beetle or fungal pests. Losses included beech, long considered the most drought-resistant.

Ten out of the 12 hottest growing seasons in the last 120 years have all happened this century. Climate forecasts already predict more of the same, with precipitation falling by a fifth by 2085. Foresters will have to think again about woodland design.

“Spruce was most heavily affected. But it was a surprise for us that beech, silver fir and pine were also damaged to this extent,” said Ansgar Kahmen of the University of Basel in Switzerland.

“We still need to study which tree species are good in which combinations, including from a forestry perspective. That will take time.”

Keeping Paris promise

And worldwide, farmers, foresters and water managers can also expect more of the same. As temperatures rise worldwide, dry seasons will tend to become drier, and wet seasons wetter.

US researchers report in the journal Nature Communications that they divided the world into nine land regions, and looked at annual rain or snowfall and how this fluctuated through the seasons in each of the nine from 1971 to 2000. They then looked at future temperature predictions for the rest of the century to see what happened to water availability.

The best outcome for relatively stable water supplies would be if nations could act to limit the planet’s average global temperature rise to no more than 2°C by 2100, in line with a promise made by 195 governments in Paris in 2015.

At higher temperatures the predicted scatter of flood and drought became more extreme. Once again, the message is: start planning. “We need to take precautions to optimally use how much water we have,” said Ashok Mishra of Clemson University in South Carolina.

“As the climate changes and population increases, we should be preparing for the future by improving the technology to efficiently use water for crops.” − Climate News Network

Cover photo by Villy, via Wikimedia Commons.
This article was originally posted on the Climate News Network.
EU project SIM4NEXUS looks to transform policymaking to achieve a resource-efficient Europe

EU project SIM4NEXUS looks to transform policymaking to achieve a resource-efficient Europe

It is no surprise that human activity has an impact on the environment. As our societies become more complex, our use of resources such as water, land, food, and energy intensifies. The products we buy, the services we use, and the diet we follow have an intense and growing impact on those resources.

The intensification of resources’ use contributes to unbalance our environment, which affects climate and biodiversity as well as resource availability. Society can no longer ignore the nexus between water, land, food, energy and climate, and how such connections directly affect our livelihood. Keeping the model of economic and technological growth as we know with the least harmful impacts on the environment is one of the biggest challenges our society faces today.

But how can we make sure that the nexus among essential resources is balanced out? How can we know where our biggest concerns should focus on? And how can we guarantee that policymakers are making the right decisions regarding our environment?

At a European level, policies play a key role in how such questions can be answered. Most importantly, being able to avoid conflicts and compromises among the water-land-energy-food climate sectors and other sectors is important for the development of efficient use of resources. For that reason, predicting the impacts of resource use is a first step towards assuring its existence.

The EU Project SIM4NEXUS advances environmental policymaking

This is where SIM4NEXUS steps in. The European Union project set up in 2016 is tackling these and other issues concerning the management of the Nexus through technology and innovation.

The research project is funded by Horizon 2020, which is the largest Research and Innovation program created by the EU. Running until this year, the SIM4NEXUS research project led by the Wageningen Economic Research in the Netherlands is addressing gaps in knowledge and technology in the nexus to facilitate the design and implementation of EU policies. The project brings together a strong multidisciplinary collaboration among 25 partners from 15 countries across Europe.

With research and innovation being at the heart of the project, SIM4NEXUS brings forward a number of key outcomes, including:

  1. A science library of integrated tools that use Artificial Intelligence (AI) and Complexity Science.
  2. A GeoPlatform that integrates data and metadata sources on all themes for decision and policy-making.
  3. A Serious Game, a user-friendly, interactive and pedagogical cloud-based interface for experts to understand the themes of the Nexus and how they interact. Experts can also test scenarios and policy choices.
  4. Building capabilities and consultancy for the Serious Game to maximize a reliable application of the game and support studies on the nexus, to help guide more informed decisions and policy choices.

SIM4NEXUS research results

To understand how policies interact and impact the nexus of water, land, food, energy, and climate, case studies are essential to have real data on the models developed during the research project. Whether at regional, national, European or global scales, SIM4NEXUS already brings success stories.

Dr. Floor Brouwer, SIM4NEXUS coordinator and environmental economist at Wageningen Economic Research, says: “We started this very clever work to look at European and global scale to understand policy coherence. I think it’s a very timely topic to understand. When you design your policy, are you adequately taking into account the different nexus sectors?”

Dr. Floor Brouwer, SIM4NEXUS coordinator

Dr. Brouwer also stresses that, although there is enough policy coherence at European and international policy debates, the biggest issue lies in the implementation of such policies. He adds, “For that reason, we have two case studies to look at Europe. We developed The Serious Game for our twelve case studies and we expect each case study to help better understand decision making, taking into account the broader perspective of water, land, food, energy, and climate”. One example of such trade-offs is that clean energy transition involves the use of bioenergy. Large scale use of bioenergy from crops, plantations and forests may however have severe trade-offs to water, land, global food security, climate adaptation and even climate mitigation, across borders and scales. Policies stimulating directly or indirectly the use of bioenergy should only be put in place if both food security and climate-neutrality are assessed.

A Serious Game for policy innovation

One of the main results of the research project is the SIM4NEXUS Serious Game. The computer game focuses on helping users understand and explore the interactions among water, energy, land and food resources management. This is the first time that a Serious Game has been built on the nexus topic.

Through the gameplay environment, users can implement policies and explore how their decisions impact the nexus in different regions. The game also considers the financial and social capital costs of implementing policies as well as their potential benefits.

The SIM4NEXUS Serious Game is under test in ten case studies in different regions in Europe. The components of the game are already accessible online for the Greek case study. On YouTube, a presentation of the game prototype is also available.

A prototype of the SIM4NEXUS Serious Game.

On different occasions, the SIM4NEXUS Serious Game was the topic of training workshops, where students could learn more about how the game works. Showcased in the “Local Mayors and Communities Exhibition” in Paris, the game received positive feedbacks from visitors and participants.

What is next

The SIM4NEXUS project approaches its end with a better understanding of how climate and sustainability goals are linked to water management, food, biodiversity, and land-use policies. Through the project, policymakers can better identify trade-offs and achieve synergies to increase the efficient use of resources.

A series of special interviews with professionals from different countries and organizations involved in the SIM4NEXUS case studies is available on the SIM4NEXUS YouTube page. Watch them and learn more about the project and the importance of the nexus.

To continue following the project’s updates and new initiatives, access the SIM4NEXUS website and follow the Twitter page.

Cover photo by Markus Tacker on Climate Visuals (CC BY-ND 2.0)