Posted on 19 September 2019
One of the most famous photos ever taken is NASA’s Blue Marble - a beautiful picture of Earth from space taken on 7 December, 1972. The brown and green of Africa makes way to the white of Antarctic ice and the vast deep blue of the ocean. While not visible in the iconic image, behind those fantastic colours is a rich diversity of life, biodiversity that is today severely threatened by climate change.
In early August this year, the Intergovernmental Panel on Climate Change (IPCC) released its Land Report, highlighting the threats to the brown and green: how our use of land drives climate change and how climate change adds stress to land and so worsens existing risks - such as to food security. And on Friday, IPCC scientists and governments from around the world will gather in Monaco to discuss the blue and white that make up two other pieces of the climate puzzle - the 71% of Earth’s surface covered by oceans and the world’s frozen places covered by snow and ice. This meeting is to approve the IPCC Special Report on Oceans and Cryosphere in a Changing Climate next week.
Climate regulation and vulnerability
While they say a picture is worth a thousand words, I wonder if any words would be enough to do justice to the vital role these wet and frozen parts of the world play in helping maintain our well-being and that of the planet.
For instance, they help to regulate the global climate. The bright white of the polar regions and snow-covered mountains reflect sunlight back into space, lessening the warming of the earth. But these regions are themselves vulnerable to climate change: this same warming leads to the ice melting. The loss of snow and ice exposes darker underlying ocean or rock, and so we go from reflecting to absorbing heat - and a potential acceleration of climate change.
The oceans tell a similar story. They slow global warming, absorbing excess heat from the atmosphere and even removing around a quarter of the carbon dioxide emissions from human activities. But absorbing heat results in warmer waters, and the dissolving carbon dioxide acidifies the ocean, making it more difficult for some plankton and coral to form their skeletons which can further impact balance within the ocean ecosystem.
Science is consistently pointing toward the fact that our oceans and frozen world are under enormous direct pressure from our activities, and are also highly vulnerable to human-induced climate change. Indeed, accelerating change in these regions are some of the most visible symptoms of the climate crisis. Scientists have recently reported shrinking glaciers on all seven continents, with devastating impacts in places such as Asia and South America where many millions of people rely on them for water.
From loss of sea-ice and melting of land-based ice sheets to rising sea levels and more intense extreme events (such as ocean heatwaves and cyclones) which can be hugely devastating to people, infrastructure and nature, we are witnessing a vast range of climate impacts. If these and other impacts are left unchecked, they will have disastrous consequences for millions of people and for the planet’s most vulnerable ecosystems.
However frightening the science may be, we still have choices which limit future climate risks despite some of them being locked in because of past and current emissions. We need to build resilience and to adapt to this crisis, and we need urgent decarbonisation - more mitigation can slow the rate and magnitude of future climate risks and help adaptations to be more effective.
The forthcoming IPCC report on Oceans and Cryosphere, as well as the recent Land Report, are stark reminders that the systems we rely upon to sustain life on the Blue Marble are losing their capacity to regulate the climate. We can't afford to let that happen.
The scale of the climate crisis is up to us and our leaders - we still stand a chance to avoid the worst if, by 2020, Governments raise the ambition of their pledges under the Paris Agreement to limit global warming to 1.5°C. While in Monaco observing the discussions, we hope to hear bold announcements in the UN Secretary General Summit that will take place in New York. We also hope countries will step up their commitments at the UN climate COP 25 in December in Chile.
The Blue Marble is in trouble but the dice is ours to roll. We need to act fast and we need to act now.
Dr Stephen Cornelius is the Chief Adviser on Climate Change and IPCC lead for WWF. He will lead the WWF team at the IPCC Special Report on the Oceans and Cryosphere in a Changing Climate approval session in Monaco. Follow him on twitter @SteveJCornelius.
WWF is an observer organisation to the IPCC.