Research Efforts Reveal Climate Change Impacts On Global Hotspots
December 17, 2013

Research Efforts Reveal Climate Change Impacts On Global Hotspots

Bryan P. Carpender for - Your Universe Online

Climate change. It’s a topic that is commonly considered controversial, and for years its very existence and effects have been debated across the globe.

"There is an elephant in the room: current and future climate change impacts. But strangely, many people seem to be blind to it," says Hans Joachim Schellnhuber, Director of the Potsdam Institute for Climate Impact Research (PIK). "Many decision makers prefer to turn a blind eye to global warming consequences, while many scientists tend to focus on very specific aspects of climate change. So we resemble the fabled blind men, who unknowingly touch different parts of the same elephant: grasping the animal's trunk, one of the men is convinced he has a snake in his hand, whilst one other mistakes the tail for a rope. To recognize the animal, they must talk to each other to properly identify the individual parts and to bring them together. This is exactly what this international project does."

Now an extensive new research undertaking is making it more difficult to ignore how adverse climate change effects on things like flood hazard, drought, water scarcity, agriculture, ecosystems, and malaria can combine to create global 'hotspots' of climate change impacts.

In a unique global collaboration, the efforts of thirty different research teams in twelve countries have yielded valuable insights and warning signs for what the future holds.

The Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) systematically compared state-of-the-art computer simulations of climate change impacts on a broad range of sectors. The project is publishing its preliminary results this week in a special feature of the Proceedings of the National Academy of Sciences (PNAS).

By performing extensive model inter-comparisons, research gaps can be identified and the resultant data can provide insights to aid in decision-making and action plans regarding the impact of future climate change.

Building on previous inter-comparison exercises from the fields of agriculture, hydrology and ecosystems sciences, the project’s results are combined to identify regional hotspots of climate change, such as the Amazon, the Mediterranean and East Africa – all places where several impact types coincide and potentially interact.

Availability of Water In Jeopardy In Certain Global Hotspots

One main issue addressed is water scarcity, which already affects millions of people worldwide. Absolute water scarcity is defined as less than 500 cubic meters available per year per person – a level requiring extremely efficient water use techniques and management in order to be sufficient; many countries do not have such measures in place.

Today, between one and two people out of a hundred live in countries with absolute water scarcity. The combination of population growth and climate change would increase this to about ten in a hundred at roughly 3 degrees global warming. By comparison, the global average water consumption per person and year is roughly 1200 cubic meters, and significantly more in many industrialized countries.

Without a reduction in global greenhouse-gas emissions, 40 percent more people may be at risk of absolute water scarcity than would be likely without climate change. Climate change is not uniform across the board; the regional differences in its impacts on water availability are huge.

"The global-level results are concerning but they hide important regional variations. For example, while some parts of the globe might see substantial increases in available water, such as southern India, western China and parts of Eastern Africa, other parts of the globe see large decreases in available water, including the Mediterranean, Middle East, the southern USA, and southern China," says Dr. Simon Gosling, from the School of Geography at The University of Nottingham.

"Water scarcity is a major threat for human development, as for instance food security in many regions depends on irrigation – agriculture is the main water user worldwide," says co-author Qiuhong Tang of the Chinese Academy of Sciences. "Still, an increase of precipitation is also challenging – the additional water may cause water logging, flooding, and malfunctioning or failure of water-related infrastructure. So the overall risks are growing."

Pavel Kabat, Director of the International Institute for Applied Systems Analysis (IIASA) and a co-author of several contributions to the study explains what sets this research collaboration apart:

"The multi-model assessment is unique in that it gives us a good measure of uncertainties in future impacts of climate change – which in turn allows us to understand which findings are most robust. From a risk management perspective, it becomes very clear that, if human-made climate change continues, we are putting at risk the very basis of life for millions of people, even according to the more optimistic scenarios and models."

However, he added, the job is far from being done. "We need to do additional research on how the water requirement portfolio will develop in the future in different sectors like agriculture, industry, and energy – and how, in addition to reducing greenhouse-gas emissions, the technological developments in the water sector may help alleviating water scarcity."

One of the core products of ISI-MIP is a public data archive, where the output, as well as the input, data from the project is available for further research and to promote maximum transparency. The ISI-MIP hopes to elevate research on climate impacts to a new level and aims to further enhance the quality of the computer models of impacts.

After the publication of its first results, the project now enters a second phase, broadening the scope of impacts considered (addressing, for example, the energy industry and global fisheries) and incorporating models that look more closely at specific regions.

Hopefully, this research will not only enable us to make more informed decisions regarding current challenges, but also communicate a sense of urgency for our collective response to adverse climate change impacts in the future.