The Paris Agreement tries to limit the temperature increase to two degrees and to 1.5 if possible, to reduce the catastrophic long-term consequences.
The World Meteorological Organization (WMO) estimates that the planet could reach the barrier of 1.5 degrees of global warming before 2024 with respect to pre-industrial levels (1850-1900). According to the climate predictions issued by this organism, there is a 20% probability that this will occur, which could have serious long-term consequences (more intense storms, melting glaciers, more dangerous hurricanes, etc.).
The Barcelona Supercomputing Center (BSC) has participated in the Global Annual to Decadal Climate Update, led by the United Kingdom’s Met Office and has contributions from climate modeling centers from ten countries. The document already places the average temperature of the Earth at a higher degree than in pre-industrial times. The past five years have been the warmest since records exist.
WMO Secretary-General Petteri Taalas believes it is critical to limit the temperature rise to two degrees, and to 1.5 degrees as far as possible, to minimize the catastrophic consequences for Earth in the long term. “This study shows – with a high level of scientific skill – the enormous challenge ahead in meeting the Paris Agreement on Climate Change target of keeping a global temperature rise this century well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius”.
This Global Annual to Decadal Climate Update offers a climate projection for the next five years and will be updated annually. To do this, climate researchers use supercomputer resources from their countries with which they can produce the best climate simulations, which are then delivered to the WMO coordination system.
The BSC has participated in this update with its multi-year global climate predictions made with the EC-Earth community model. These predictions are carried out on the MareNostrum 4 supercomputer and use the experience developed in recent years at the BSC.
Francisco Doblas Reyes, ICREA professor and director of the BSC Earth Sciences department, underlines that “this new instrument that climate research centers make available to governments and society through the WMO represents an opportunity to illustrate the importance of the need to consider adaptation to climate change in the short term, of addressing the challenge of mitigating greenhouse gas emissions, and of the importance of international collaboration to meet the needs of climate information. The BSC tries to address these requirements with its research geared to the needs of society”.
The predictions models take into account natural variations, as well as human influence on the climate, to obtain the best possible predictions of temperature, rain, wind patterns and the evolution of the climate system for the next five years. In contrast, changes in greenhouse gas and aerosol emissions during confinement due to the COVID-19 pandemic have not been taken into account, although its impact on a global scale is considered to be of little relevance. The small influence of the pandemic on the climate system offers a measure of the challenge of addressing global temperature limitations in the coming decades.
Adam Scaife is the head of long-range prediction at the Met Office Hadley Centre. He stresses: “This is an exciting new scientific capability. As human-induced climate change grows, it is becoming even more important for governments and decision makers to understand the current climate risks on an annually-updated basis.”
Highlights
- Annual global temperature is likely to be at least 1°C warmer than preindustrial levels (defined as the 1850-1900 average) in each of the coming 5 years and is very likely to be within the range 0.91 – 1.59°C
- There is a ~70% chance that one or more months during the next 5 years will be at least 1.5°C warmer than preindustrial levels
- There is a ~20% chance that one of the next 5 years will be at least 1.5°C warmer than preindustrial levels, but the chance is increasing with time
- It is extremely unlikely (~3%) that the 5 year mean temperature for 2020-2024 will be 1.5°C warmer than preindustrial levels
- Over 2020-2024, almost all regions, except parts of the southern oceans, are likely to be warmer than the recent past
- Over 2020-2024, high latitude regions and the Sahel are likely to be wetter than the recent past whereas northern and eastern parts of South America are likely to be dryer
- Over 2020-2024, sea-level pressure anomalies suggest that the northern North Atlantic region could have stronger westerly winds leading to more storms in western Europe
- In 2020, large land areas in the Northern Hemisphere are likely to be over 0.8°C warmer than the recent past (defined as the 1981-2010 average)
- In 2020, the Arctic is likely to have warmed by more than twice as much as the global mean
- The smallest temperature change is expected in the tropics and in the mid-latitudes of the Southern Hemisphere
- In 2020, many parts of South America, southern Africa and Australia are likely to be dryer than the recent past