Extract from The Guardian
Dramatic increases in the rate at which ice on Greenland and East Antarctica
is melting are, along with the heatwave gripping Australia, among the
latest manifestations of the changes our planet and its atmosphere are
undergoing. Concerns surrounding the risk of melting ice causing sea
levels to rise were previously focused mainly on large glaciers. But
scientists have discovered that the largest recent losses from
Greenland’s vast ice sheet, which is two miles thick in places, have
occurred in the island’s largely glacier-free south-west. Combined with
recent analysis of retreating Antarctic glaciers that were previously
thought to be stable, this new research makes unnerving reading. This is
because of what it tells us about the extent of likely sea level rises,
and warming seas linked to coral die-off and chaotic weather, but also
because it highlights the difficulty of fully understanding the climate
system.
Last year the UN’s Intergovernmental Panel on Climate Change urged governments to work towards the most ambitious targets in the 2015 Paris agreement, and a global temperature rise not greater than 1.5C. Many experts fear that factors including the election of Donald Trump in the US and Jair Bolsonaro in Brazil mean that even the more modest goal of sticking to current commitments, putting the world on course for a 3C rise, remains a huge challenge. Currently, global carbon emissions are still rising. But if people all over the world are getting used to the idea that higher temperatures and increased frequency of extreme weather events are the new normal – recent polling in the US suggests 72% of Americans believe global warming is important, the highest-ever figure – we are arguably less advanced in our understanding of warming oceans.
The sea level rises that scientists expect to accompany a temperature rise of 3C
would submerge cities including Shanghai, Osaka and Miami along with
parts of Rio de Janeiro and Alexandria – less than a century from now.
Among nations, Bangladesh will be particularly severely affected, with
one estimate suggesting that 250,000 people are already forced to move
each year, making them environmental refugees.
Such facts on the ground, as well as predictions, are why climate
activists have long linked their cause to wider concerns around social
justice. Just as carbon emissions must be limited to protect the
livelihoods of people already struggling in areas vulnerable to drought
and desertification, sea level rises must be restricted to protect the
millions of people who live on coasts and in low-lying areas. The
movement of peoples around the world, including but not limited to
refugees, is in some cases a direct consequence of changes to the
environment.Last year the UN’s Intergovernmental Panel on Climate Change urged governments to work towards the most ambitious targets in the 2015 Paris agreement, and a global temperature rise not greater than 1.5C. Many experts fear that factors including the election of Donald Trump in the US and Jair Bolsonaro in Brazil mean that even the more modest goal of sticking to current commitments, putting the world on course for a 3C rise, remains a huge challenge. Currently, global carbon emissions are still rising. But if people all over the world are getting used to the idea that higher temperatures and increased frequency of extreme weather events are the new normal – recent polling in the US suggests 72% of Americans believe global warming is important, the highest-ever figure – we are arguably less advanced in our understanding of warming oceans.
Weather and climate systems are complex, and sea levels are hard to predict confidently. Already, ice sheets and glaciers are surprising scientists by behaving in unexpected ways. But while trying to limit future emissions remains the most pressing task, these ominous findings highlight the need to address the consequences of carbon already emitted. Sea level rises will continue long after emissions have peaked. We will have to adapt to our world’s changing shape.
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