The main cause of global warming is the current concentration of carbon dioxide in the air, which in turn is caused by the release of fossil CO2. In fact, since the 18th century we have been extracting from the ground and burning increasing amounts of coal, oil and gas.
The global average temperature has increased by 1.1°C compared to the pre-industrial period, before we started burning fossil fuels putting new CO2 into the atmosphere. The average temperature of the planet has increased by 0.2°C compared to the period 2011-2015.
Nearly all land surfaces are experiencing more hot days and heat waves; 2020 was one of the hottest years on record. Rising temperatures increase heat-related illnesses and can make it more difficult to work and travel. Fires are more likely to break out and spread more quickly in hot weather.
There are no signs of a trend reversal, and this is leading to a long-term climate change, which will result in rising sea levels, ocean acidification, more extreme weather events, and a series of other very serious consequent phenomena, such as the progressive loss of biodiversity due to the disappearance of a huge number of species that will not be able to adapt to the new environmental context. A perspective now confirmed by an endless number of scientific studies.
As we unfortunately know, the Covid-19 pandemic also disrupted the 2020 Climate Agenda with the postponement of COP26 in Glasgow until next year, so the last WMO Bulletin published on 23 November 2020 was overshadowed by news updates on the evolution of Covid-19 and the measures to be taken to contain it.
WMO Secretary-General Petteri Taalas said that carbon dioxide stays in the atmosphere for centuries and in the ocean even longer, and that the last time the Earth experienced a comparable concentration of CO2 to today was 3-5 million years ago, when the temperature was 2-3 °C warmer and the sea level was 10-20 metres higher than now. But there weren’t 7.7 billion inhabitants.
We exceeded the global threshold of 400 parts per million in 2015 and only four years later, we exceeded 410 ppm. Such a rate of growth has never been seen in the history of our data. The decline in emissions related to the freeze is only a minor drawback in the long-term graph. We need a sustained flattening of the curve.
2020 trends
The Global Carbon Project (GCP), the international organisation of scientists whose aim is to support studies to monitor greenhouse gas emissions and estimate how much CO2 can be emitted into the atmosphere to keep the temperature from rising by more than 2 °C, calculated that during the most intense period of the anti-COVID freeze, daily CO2 emissions would be reduced by 17% globally due to population containment. As the duration and severity of the containment measures remain unclear, the forecast of the total annual emission reduction in 2020 is still uncertain. The GCP will publish its annual update on global emissions trends in December.