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Climate vulnerable forum
Over the last three years, climatologists have changed the definition of what they believe to be the "safe" limit of climate change.
For decades, researchers have argued that the increase in global temperature should be kept below 2 ° C by the end of the century to avoid the worst impacts.
But scientists now argue that staying below 1.5 ° C is a much safer limit for the world.
Everyone agrees that staying below that goal will not be easy.
This week in South Korea, researchers will report on the feasibility and costs associated with achieving this lower limit.
Scientists from the Intergovernmental Panel on Climate Change (IPCC) meet in the city of Incheon to develop a plan, in cooperation with government delegates, on steps to be taken to achieve this new goal.
So, why has the goal changed?
In a word – politics.
The idea of two degrees as a safety threshold for warming has evolved over the years from the first mention recorded by the economist William Nordhaus in 1975.
It was during the climate negotiations in Paris that the goal of 1.5 ° C became reality
In the mid-1990s, European ministers had signed the two-degree limit and, in 2010, it was the official policy of the UN. Governments agreed in Cancún to "maintain the increase in global average temperatures below two degrees".
However, small island states and low-lying countries were very unhappy with this prospect because they thought it meant that their territories would be inundated with seawater, as rising temperatures caused more ice to melt and the expansion of the seas.
They commissioned a study that showed that preventing temperatures from exceeding 1.5 ° C would give them a chance to fight.
At the unhappy climate summit in Copenhagen in 2009, climate-vulnerable countries claimed a lower figure, but their efforts were doomed to failure after the collapse of the conference.
But the idea has not completely disappeared – and at the time of the Paris negotiations in 2015, it had become a priority as French diplomats sought to form a broad coalition of rich and poor countries that would support an agreement. .
It worked.
What difference does a half-degree actually make?
More than you think!
The summary leakage projects for IPCC policymakers, which will be released after a week of bargaining with government delegates in South Korea, point to major differences in terms of impact on the world of trade. versions 1.5 and 2C. We have summarized the main ones here:
"Two degrees are no longer the two degrees we thought we would be," said Kaisa Kosonen of Greenpeace, following the evolution of the IPCC's 1.5C report.
"As a climate-related goal, it becomes increasingly meaningless when you look at the risks that come with it and what we are already seeing with a degree – why would you want a goal that does not protect anything? what is important to us? "
How will it be difficult to stay below the limit?
Very – the world has already warmed by about a degree and, according to the drafts of the 1.5 report, we will exceed this limit by 2040.
The new IPCC report will not tell governments what to do, but will instead expose a range of approaches that will likely involve strong carbon emission reductions, a rapid transition to renewable energies and changes in the mode of carbon emissions. life and food.
What happens if we go beyond 1.5?
The IPCC spent a lot of time looking at this issue and came up with a clever plan!
In their draft reports, they talk about "overshoot", which means that in many scenarios they expect temperatures in excess of 1.5, but they believe they can be recovered below the limit. using a range of technologies to remove carbon dioxide from the air – the latter. range from planting trees to more complex and untested machines.
Some experts believe, however, that this approach presents considerable risks.
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UNFCCC
Climate activists have been pushing for 1.5C for several years
"A species that will disappear at two degrees will still be if you go down to 1.5 ° C," said Dr. Steven Cornelius of WWF, former British government negotiator for the IPCC.
"Some things may come back, but some things are irreversible, that is, they take a risk that you want to try to keep below 1.5, which clearly means that the reductions in Emissions will be faster and deeper sooner, which will likely mean elimination of carbon dioxide technologies – some of them we know what to do, but others are causing and need to be evaluated . "
Are there any encouraging signs?
Surprisingly, yes!
While the task of limiting the rise in global temperature to 1.5 ° C during this century is enormous, some indicators on the horizon show that some governments recognize the seriousness of the problem and are taking steps to make it happen. face.
Just a few days ago, the British government committed to achieving zero net emissions by 2050 by joining 18 other countries in the Carbon Neutrality Coalition.
Some environmentalists estimate that it is possible to maintain temperatures at 1.5, without resorting to mechanical devices or planting billions of trees.
"If we get very fast emission reductions and this is accompanied by a massive intensification of land restoration and changes in our food system to reduce meat consumption, we can reach 1.5 ° C to create a lot of well-being for the people, "said Hannah Mowat of Fern.
"This creates a better air and reduces the levels of obesity.It is a world in which we want to say yes, rather than a further industrialization of our landscapes."
