The climate summit faces its second and final week of negotiations. The representatives of the almost 200 countries gathered in Glasgow discuss in which world the human being will have to live in the next decades. The objective is to break with the growing trajectory of greenhouse gas emissions, so that warming does not move towards 4 degrees and can be kept within the safety margin set by scientists, between 2 and 1.5 degrees . The problem? That requires nations to drastically and urgently reduce their consumption of fossil fuels, the staple of economic growth.
The Glasgow negotiations are taking place in a context of scientific alert. The latest major report from the IPCC – the group of scientists who radiographs warming under the UN umbrella – warned that extreme weather events are becoming more intense and frequent. But he recalled that the warming can still be contained. For this IPCC report, an atlas with the consequences of warming in different emission scenarios. In other words, a map of “possible future worlds”, as explained by José Manuel Gutiérrez, director of the Institute of Physics of Cantabria and coordinator of this project in which the CSIC and the technology company Predictia participate.
Based on the data from this work, EL PAÍS has developed a map that allows exploring the predictions of the scientists of temperature, drought and rain, in each region of the planet, and in the three scenarios: pessimistic, intermediate and optimistic. Here you can browse the possible futures possible.
The future if things stay the same
In a pessimistic scenario, with emissions that do not slow down and continue with the current increasing rate, what the predictions of the IPCC models predict is an accelerated warming that would lead to an average increase in global temperature of 4 degrees. It is useful to imagine a girl and her grandfather, both from Spain or Italy.
Throughout his life, the grandfather has seen the temperature rise by one or two degrees since 1950. On the other hand, in the pessimistic scenario of emissions, his granddaughter would see a rise of 4 degrees from 2010 to 2080. The grandfather has seen how extreme heat passed from 4 to 10 days per year; the granddaughter will see them reach 33. The periods of drought have not changed much during the life of the old man, but his granddaughter could see them go from 80 to 96 days on average.
The future if we act
The optimistic scenario consists of applying drastic and rapid plans to reduce greenhouse emissions, until their practical elimination from the second half of the century. That is the objective of the Paris Agreement, which seeks that global warming remains between 1.5 and 2 degrees compared to pre-industrial levels (now we are already at 1.1 degrees).
Because, after two centuries of increasing emissions of gases that will remain in the atmosphere for many decades, what humanity can aspire to at this time is to limit the increase in temperature, but not to reverse it.
The fight against climate change is a matter of territorial and generational justice. Territorial because warming will do the most damage to those with the least responsibility: the poorest countries that have emitted the least. And generational because the worst consequences of systematically ignoring scientific warnings about greenhouse gases will be faced by future generations.
Although climate change is unstoppable, it is still possible to decide the dimensions of our heritage. For example, in a world with moderate warming – two degrees of global average increase – the days of extreme heat that that granddaughter we were talking about would suffer in 2070 would go from 33 in the pessimistic scenario to 14.
The same would happen with droughts: that girl would suffer some 80 days in the optimistic scenario, a figure like the current one, compared to 96 in the alternative world in which humanity preferred to continue ignoring the alerts and burning fossil fuels.
And where are we headed now?
If the countries’ short and medium-term plans are taken into account, the pace that emissions will take during this decade will lead to a warming of about 2.7 degrees, according to the latest evaluation carried out by the United Nations. In other words, countries need to further toughen their emission cut plans. However, if you take into account the long-term goals that nations are setting for themselves – for the middle of the century – and the promises made at the summit in the first week, the International Energy Agency argues that it could be in the right direction. 1.8 degree path.
The problem is that these promises and goals for the future do not match in many cases with the concrete plans to cut emissions between now and 2030. Anne Olhoff, the economist who has coordinated the analysis reports of the national programs of greenhouse gas cuts for the UN, summed it up this week to EL PAÍS: “What really matters is that the promises are backed by short and medium-term measures that provide confidence that they can be achieved.”
Methodology
Scenarios. We have considered three greenhouse gas emission scenarios. SSP1-26 is an ambitious scenario, which would allow limiting the level of global warming to below 2 degrees (as stated in the Paris Agreement). The SSP2-45 is an intermediate scenario, and the SSP5-85 is the worst, with the highest level of emissions, which would raise the planet’s temperature by 4 or 5 degrees. You can read about the scenarios in the IPCC documents.
Climate variables. We have used four metrics: the average temperature, the number of days per year with temperatures exceeding 40 degrees, the average annual precipitation in mm / day, and the consecutive days of drought (less than 1 mm).
Uncertainty. We have summarized each metric with a point prediction: the median predictions from the battery of dozens of models used by the IPCC Atlas.
Has contributed to this information Luis Sevillano Pires.
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