During this period, the climate movement experienced very worrying headwinds. President Donald Trump officially withdrew the United States from the Paris climate accord in November 2020 – the only country to do so – while President-elect Joe Biden promised to reinstate the first day of his term in January 2021. On November 4, 2019, the United States informed the custodian of its withdrawal from the agreement, which will take effect exactly one year after that date.  The widespread failure to combat the existential threat of climate change has led more than 11,000 scientists from 153 countries to sign a “World Scientists” warning of a Climate Emergency declaration. Whatever the report on climate promises, the statement begins: “Scientists have a moral obligation to clearly warn humanity of any catastrophic threat and to say it as it is.” A preliminary inventory-impact study was published in Nature Communications in April 2020. Based on a public policy database and a multi-model scenario analysis, the authors showed that the implementation of current strategies by 2030 leaves an average emission gap of 22.4 to 28.2 GtCO2eq, with optimal means to achieve targets well below 2 degrees Celsius and 1.5 degrees Celsius. If national contributions were fully implemented, this gap would be reduced by one-third. The countries assessed did not achieve their promised contributions with implemented measures (implementation deficit) or experienced a gap in ambition with optimal paths to well below 2oC. The study showed that all countries should accelerate the implementation of renewable technology strategies, while improving efficiency in emerging and fossil fuel-dependent countries is particularly important.
 Most of the 2030 CO2 emission reduction commitments, made by 184 countries under the Paris Agreement, are far from enough to keep global warming well below 3.6 degrees Fahrenheit (2 degrees Celsius). Some countries will not meet their commitments and some of the world`s largest CO2 emitters will increase their emissions further, according to a group of world-class climate scientists. But without the United States, the balance between the parties that signed the Paris agreement shifts in China`s favor on key issues that have not yet been resolved. According to Michael Oppenheimer, a climatologist at Princeton University in New Jersey, China could resist demands for follow-up and detailed reports on how countries implement their policies and achieve their goals. “It doesn`t bode well for the effectiveness of the Paris agreement,” he says. His view on the Paris agreement was that it was unfair to the United States, so countries like India and China were free to use fossil fuels while the United States had to reduce its carbon. Iran, Iraq and Libya – all members of the Organization of Petroleum Exporting Countries (Opec) – and conflict-torn states such as Yemen and South Sudan have not ratified the agreement. All remaining parties to the agreement must present their new 2030 targets before the next major UN climate meeting, to be held in Glasgow, UK, in November 2021 (this year`s climate summit has been postponed due to the pandemic).