Climate change – Mapping the world’s most and least vulnerable areas

An international team of biologists has created a world map showing which regions are most and which are least vulnerable to climate change. The biologists note that this is one of the key areas that will be examined next year in a report by the Intergovernmental Panel on Climate Change whose latest report on the science of climate change was released last month.

In a report of their research, published in Nature Climate Change, the team says that until now, most assessments of how future climate change will affect land and seascapes have been incomplete.

This is because those preparing the assessments have not properly factored in how the landscapes have already been modified by human activities such as land clearing.

“Too often, assessments that have been done on future climate vulnerability have looked at the Earth as a blank slate, rather than a planet with vastly different landscapes depending on where humans have settled,” the biologists say.

“What we found was that when you combine data on how humans have already changed the land we live on, together with future projections of climate changes, you get quite different results to what previous vulnerability maps have shown. It’s a map that we believe can help guide decisions about the best places to start for cost-effective conservation.”

The three biologists from the Wildlife Conservation Society, Stanford University in the United States and the University of Queensland in Australia note that species around the world are already adapting to climate change.

“Humans are leading the way in various ways including through natural resource management and, as a result, we’re witnessing large-scale changes across the planet. For instance, people are changing their agricultural activities because of changing rainfall in the mountains of the Albertine Rift and the valleys of the Congo Basin in Africa while across the Pacific, local communities are constructing seawalls to slow down the impact of higher king tides and sea-level rise.”

But the researchers say that humans' ability to adapt to change has significant consequences for other species. Increased agricultural production in Africa is causing widespread loss of essential species habitats, including the critically endangered mountain gorillas.

Building seawalls has led to the wholesale destruction of some of the most biodiverse coral reefs in the world while increased human access to polar regions is wreaking havoc on delicate biodiversity – with reported declines in shorebirds, seabirds and mammals.

“Research has usually focused on individual species’ exposure to temperature increase, without considering the fact that what makes a species vulnerable is also a consequence of how sensitive a species is (which varies from species to species) and their adaptive capacity (which, among other things, relates to whether they have a healthy population overall),” the researchers say.

Almost all assessments also discount the fact that a global extinction crisis is occurring, while most science reports do not consider the fact that many species are already vulnerable because of the past and current actions undertaken by humans. This means that scientists do not really know where species are most vulnerable, what actions are needed or which ones would be most cost-effective.

Value of new ‘vulnerability map’

In preparing their new ‘vulnerability map’, the researchers took into account how intact vegetation currently is in different regions, and then considered how stable ecosystems were expected to be under predictions of future climate change. They then found that the regions likely to be the most vulnerable to climate change were quite different to previous studies.

These were, in fact, southern and south-eastern Asia, western and central Europe, eastern South America, and southern Australia. The analysis differs from previous climate change assessments which were based on only climate change exposure and where often the most vulnerable regions were identified, such as central Africa, northern South America and northern Australia.

“Having come up with this new way of assessing regional vulnerability to climate change, we can start to identify the best ways to better conserve and manage different parts of the world. This moves us away from the assumption that all adaptation actions are suitable everywhere towards matching actions to target situation,” the researchers write.

“Ecosystems with highly intact vegetation and high relative climate stability are arguably the best locations for spending money on future protected areas, as these have the best chance of retaining species.

“In contrast, ecosystems with low levels of vegetation and high relative climate stability could merit efforts at habitat restoration whereas those with low climate stability would be most at risk and would require significant levels of investment to achieve conservation outcomes.”

The authors says that what is needed is the recognition that current ‘climate-blind’ planning is unlikely to be effective and that there is an urgent need to undertake ‘climate-smart’ assessments. This would include assessing the best places to do conservation activities such as restoration, while recognising that some landscapes might not be a good conservation investment.

“We need to be pragmatic about how we spend our money on conservation and we need to always consider that humans are continually adapting to climate change. With the right planning and investment, it should be possible to keep intact large, climate-resilient landscapes that we have identified in this study.”