The scenario is much worse than we imagined. According to the forecasts established in the Paris Agreement of 2016, the temperature of the Earth would not rise more than 2 ºC by the end of the century. A new study carried out by researchers from the University of Washington (USA) and other institutions opens our eyes to reality: global warming will cause the average temperature of the Earth to be between 3-5 ° C higher by 2100 high.
Far from the goal of limiting the increase in the Earth’s temperature by 2ºC compared to pre-industrial levels, humans will face much higher average temperatures.
The statistical study shows only a 5% chance that the Earth will warm 2 degrees or less by the end of this century. Limiting the rise to 1.5 ° C reduces to a 1% probability in the most realistic scenario. And is that, according to the results published in the journal Nature Climate Change , the human being will face an increase of between 2 and 4.9 º C, above what is established in the aforementioned Paris Agreement.
“Our analysis is consistent with previous estimates, but shows that the most optimistic predictions are unlikely to be fulfilled. Overall, the targets expressed in the Paris Agreement are ambitious but realistic, but the bad news is that they are unlikely to be sufficient to deliver. be able to keep warming at or below 1.5 ° C, “says Adrian Raftery, leader of the work.
Reaching the scenario of a rise of just 2 ° C “is feasible, but only with significant and sustained effort on all fronts over the next 80 years, ” according to Raftery.
The figures do not lie. The new projections show a 90% probability that temperatures will increase this century between 2 and 4.9 ºC.
Study variables
Researchers have analyzed how emissions would increase by 2100 based on three key variables: per capita gross domestic product, total world population, and the amount of carbon emissions emitted by each economic activity.
Using statistical projections for each of these three quantities based on 50 years of previous data from countries around the world, the study finds a mean value of 3.2 ° C of warming in 2100.
“Countries advocated the 1.5 C target due to the severe environmental impacts that would result from exceeding that threshold. If it is exceeded, extreme heat damage, flooding from rising sea levels will be a lot more serious, ”explains study co-author Dargan Fierson.
“Our results show that in order to achieve the objectives of the Paris Agreement, drastic changes are required ,” Fierson says.
Raftery previously worked on United Nations projections for future world population. Their 2014 study used Bayesian statistics to show that the world’s population is unlikely to stabilize this century. T he planet is likely to reach 11,000 million people by 2100. However, population growth is not the determining factor causing this situation of increased heat, since most of the increase in population will occur in Africa, that uses few fossil fuels.
What matters most is the amount of carbon emissions produced for every dollar of economic activity. That value has decreased in recent decades as countries increase efficiency and enact standards to reduce carbon emissions, but how quickly this value decreases in the coming decades will be crucial in determining future warming of our planet.
Referencia: Adrian Raftery, et al. Less Than 2ºC Warming by 2100 Unlikely, Nature Climate Change (2017). DOI: 10.1038/nclimate3352
