The evidence is more certain than ever, says Professor Lesley Hughes – climate change is happening now, and the world needs to act to protect human and natural systems.
Orginally published on Climasphere
I started to become interested in the potential impacts of climate change on species and ecosystems in the early 90s. Back then, the prospect of actually measuring climate change impacts seemed a very long way off – more of an interesting hypothetical than a reality. Fast-forward to 2014 and we are in that reality.
Australia is a wonderfully diverse place. From the startling beauty of the Great Barrier Reef, to the south’s majestic cool temperate rainforests and the sweeping outback deserts in between, ours is one of the most biodiverse countries in the world. Unfortunately, this biodiversity faces grave risks.
Scientists are more certain than ever that climate change is affecting both human and natural systems all over the world. Plants and animals have proved extraordinarily sensitive to warming of only a fraction of a degree. Some species have moved hundreds of kilometres, others are experiencing changes in their life cycles and populations. But there are limits to how species will adapt to this rapidly changing world – many will simply not be able to keep pace with the changes, and face a greatly increased risk of extinction. As ecosystems decline, the services these systems provide us will also deteriorate.
But the human species also faces great risks. Australians have just experienced a record-breaking summer with over 150 climate-related records broken around the country in just 90 days. Many parts of the country also experienced extreme weather events including bushfires, heatwaves, and major flooding. These are examples from just one country – the latest IPCC Working Group II Assessment Report contains examples from around the world.
The IPCC (Intergovernmental Panel on Climate Change) is recognised as the global authority on climate change. The latest report was developed over five years by hundreds of scientists from over 70 countries. The report underwent four drafts, each of which was subject to extensive review, receiving more than 48,000 comments from more than 1,700 expert and government reviewers. The final version of the Summary for Policymakers was approved line-by-line by member countries prior to its release on 31 March 2014.
The report provides even more evidence that climate change is causing impacts, and warns of future risks. Eight key risks for Australia were identified:
- Extensive and permanent damage to coral reef systems, including the iconic and World Heritage-listed Great Barrier Reef and Ningaloo Reef.
- Loss of mountain ecosystems and increased species extinctions due to increasing temperatures and fire risk. Some alpine areas may increasingly see winters without snow.
- Increased loss of life, damage to property, and economic loss due to bushfires in southern Australia
- Limited water resources in southern Australia
- Increased frequency and intensity of heavy rainfall causing flooding, particularly in the north and west of the country
- Mortality, morbidity and infrastructure damage from heatwaves
- Increased damage to coastal infrastructure and low-lying ecosystems with rising sea levels
- Reduced agricultural productivity in the southwest, southeast, and the Murray Darling Basin, if projections of ongoing drying are realised
Effective adaptation measures will reduce some of these risks, but unless rapid and substantial emissions reductions take place, the dangers will continue to escalate. The question then becomes – when might we face impacts to which we simply cannot adapt?
People often ask – “Are you optimistic about the future?” To be honest, my answer depends on the day! Humans are smart and inventive, and we have the technology to produce clean, renewable energy. We understand the science behind the problem – let’s just hope we can come together with the collective will to enact the solution.