By James Watson; Nathalie Butt, and Takuya Iwamura, Stanford University
2 October 2013 – As the dust settles on the latest Intergovernmental Panel on Climate Change (IPCC) report on the science of climate change, the obvious question is: what do we do next?
Our research, published in Nature Climate Change in September, uses a new approach to map which parts of the world are most and least vulnerable to climate change – one of the key areas being examined in the next IPCC report on climate impacts, adaptation and vulnerability, due out in March next year.
- Photo: Building protective sea walls using coral reef that has been blasted is now a common practice in some islands off northern Papua New Guinea. Joe Walston
Up until now, we argue that most assessments of how future climate change will affect our land and seascapes have been incomplete, as they haven’t properly factored in how those 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.
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.
How we’re already adapting to change
Around the world, species 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 due to changing rainfall in the mountains of the Albertine Rift and the valleys of the Congo Basin in Africa. On islands off Australia and across the Pacific, local communities are constructing seawalls to slow down the impact of higher king tides and sea-level rise.
In the Arctic, mining activities and transport routes are on the increase as sea-ice retreats. Dutch architecture has evolved in a completely new direction, designing and producing floating homes and other buildings as a way of avoiding flood damage and destruction (a possible solution to flooding in other countries too).
But humans’ ability to adapt to change has significant consequences for other species. The 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. The increased human access to polar regions is wreaking havoc on its delicate biodiversity – with reported declines in shorebirds, seabirds, and mammals. And the large-scale development of floating infrastructure has potentially detrimental impacts on water quality and ecology through over-enrichment of water, known as “eutrophication”.
A race against time
To date, conservation science has not been strong on planning for how biodiversity can persist under changing and future climates.
Research has usually focussed 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).
Moreover, almost all assessments discount the fact we are in the midst of a global extinction crisis: most of the science we produce does not consider the fact that many species are already vulnerable because of the past and current actions undertaken by humans. There are serious ramifications to this oversight.
Most obviously, it means that we don’t really know where species are most vulnerable, what actions we need to take, and which actions are most cost-effective.
Deciphering a new map for the future
Our new vulnerability map took into account how intact vegetation currently is in different regions, and then considered how stable that ecosystem is expected to be under predictions of future climate change.
And our findings on which parts of the world are likely to be the most vulnerable to climate change turned out to be quite different to previous studies.
Our map identifies southern and southeastern Asia, western and central Europe, eastern South America, and southern Australia as some of the most vulnerable regions. The analysis differs from previous climate change assessments, based on only climate change exposure, which often identify the most vulnerable regions as central Africa, northern South America, and northern Australia.
Having come up with that 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.
Taking the next step
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.
Good examples of places like that include the Kimberley in north-western Australia, the Great Western Woodlands in south-west Western Australia and other large intact ecosystems that are features of Australia’s outback.
In contrast, ecosystems with low levels of vegetation and high relative climate stability could merit efforts at habitat restoration. Ecosystems with low levels of vegetation intactness and low climate stability would be most at risk and would require significant levels of investment to achieve conservation outcomes.
Southern Australia is one of the most vulnerable regions in the world and it is obvious that there is huge pressure on natural resources and biodiversity from human activity here. However, this does not mean we should give up on the region.
What is needed is the recognition that current “climate-blind” planning is unlikely to be effective and that there is an urgent to undertake “climate-smart” assessments. This would include assessing the best places to do conservation activities such as restoration, while recognising that some landscapes may not be a good conservation investment.
In vulnerable regions we need to recognise that tough calls need to be made. This is best done with a clear conservation objective and by factoring in the cost of implementing climate-smart actions and the likelihood of success.
However, our global analysis shows Australia to have fantastic opportunities for future adaptation, as most of Australia is relatively stable and relatively intact compared to other continents.
As highlighted in a recent series of publications in Trends in Ecology and Evolution, 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.