It was in 1992 when the United Nations Framework Convention on Climate Change instituted World Climate Day to alert about a situation that, 30 years later, has become a reality that is already affecting human well-being, ecosystems, biodiversity and the water cyclewhich increases the scarcity of water resources throughout the world.
Las causes of climate change are known and there is a scientific consensus on them: the burning of fossil fuels -coal, oil and gas-, in recent centuries has generated an accelerated accumulation of gases such as CO2, methane and others in the Earth’s atmosphere.
These gases, defined as greenhouse gases or GHGs, have the ability to retain heat that is reflected by the Earth. they act as one manta that prevents the energy projected on the planet by solar rays from returning to space.
In this way, in the last 300 years, from the beginning of the industrial Revolutionthe global average temperature has increased by 1.2 degrees, according to the latest IPCC report published in March 2023.
The percentage of GHG in the atmosphere already reaches 420 ppm or parts per million, according to the US National Oceanic and Atmospheric Administration (NOAA)at the end of 2022. It must be taken into account that in the last 800,000 years this figure has not exceeded 300 ppm and that this increase is due to human action by burn fossil fuelsthat is, by suddenly releasing into the atmosphere the CO2 accumulated in the subsoil during long geological periods of life on Earth.
As a consequence of this increase in greenhouse gases and, therefore, energy in the atmosphere, we are creating a more unstable climate system.
In recent years we have seen significant climate change effects, with especially notable impacts on a local and regional scale. An increase in the average temperature of the planet has been observed, as well as alterations in precipitation patterns, in sea levels, as a consequence of the melting of glaciers and the poles, and in the frequency and severity of extreme climatic events such as hurricanes, droughts and floods.
To combat these climatic variations, the most direct way is to mitigate the causes, that is, to rapidly reduce the gas emissions that cause global warming. This means carrying out a transformation of the global energy system, substituting fossil fuels for renewable sources, green energy or that do not emit CO2.
In March 2023, the highest scientific authority on the matter, the Intergovernmental Panel of Experts on Climate Change (IPCC), a consultative body of the UN, presented its latest report, which reflects the scientific consensus on global warming and on the measures to be adopted.
This report summarizes the previous partial reports issued in the last eight years and is the latest review of global knowledge on climate change since the so-called Paris Agreement was approved in 2015.
This international agreement called for reducing greenhouse gas emissions to ensure that by 2100 temperatures would not exceed the recommended safety margin of 1.5 degrees or, at most, 2 degrees. But the current emissions regime ventures a panorama for the end of the century that will far exceed that horizon and can reach four degrees.
The 2023 IPCC report urges undertake deep and rapid emissions reductions. In order for global warming to remain below 1.5 degrees by the end of the century, global greenhouse gas emissions must have fallen by 43% by 2030 compared to 2019 levels, 60% by 2035 and a 84% in 2050, says the IPCC.
In addition to reducing emissions, it is essential stimulate resilience and adaptation to the new climatic situation, a reality that is already here.