"The extreme weather events and patterns we've seen in recent years, not to mention the past few weeks, underscore the heightened urgency with which we must address the climate crisis," said researcher Philip Duffy, study co-author and executive director of Woodwell Climate Research Center, based in Massachusetts. Researchers also from the University of Oregon and the Virginia Institute of Biological Sciences, summarised the findings in a series of articles published in the journal BioScience, and all agreed that the effects of the climate crisis are all too obvious. Among the warning signs, researchers pointed out that 2020 was the second warmest year on record, while the five warmest years in history have occurred since 2015.

In addition, three major greenhouse gases, carbon dioxide, methane and nitrous oxide, reached record atmospheric concentrations last year and this year as well. "There is growing evidence that we are approaching or have gone beyond the tipping points associated with important parts of the Earth's system, including warm water coral reefs, Amazon rainforest and West Antarctica and Greenland ice sheets," he said. University of Oregon ecology professor William Ripple.

Scientists have proven that the coincidence of so many reports of extreme natural events, such as fires in California or floods in Central Europe, is a response to the rapid deterioration of the climate. As an example, they cited the four million hectares that burned in the United States in 2020 or one million hectares lost in the Brazilian Amazon in the same year.

"Policies to combat the climate crisis or any other symptom must address the reason: human overexploitation of the planet," warned Ripple.

The study's authors suggested that profound changes in human behavior will be needed to meet the challenges of the "climate crisis", a term agreed upon by more than 11,000 scientists in 2019 to refer to what was previously known as "global warming". Among the recommendations, they encouraged the "phasing out and eventual ban" of fossil fuels, as well as the development of strategic climate reserves. When the global economy stalled in the first half of 2020 due to the Covid-19 pandemic, certain levels fell, but global gross domestic product is expected to "recover to an unprecedented level" and with it all pollutant emissions, they indicated.