One day after the US officially announced it was withdrawing from the Paris Climate accord, more than 11,000 scientists from 153 countries warned of "untold human suffering" caused by global warming.
The scientists signed a study published on Tuesday in the peer-reviewed journal BioScience that addressed the urgency of acting on climate change.
"We declare, clearly and unequivocally, that planet Earth is facing a climate emergency," their statement said, adding that global leaders had failed to address the predicament "despite 40 years of global climate negotiations".
The study laid out six key areas in which government, businesses and the public can make changes, including replacing fossil fuels with clean and renewable energy, reducing emissions of short-lived pollutants, restoring the earth's ecosystem, consuming more plant-based foods and reducing the world's population.
Phoebe Barnard, one of the lead authors of the report and the chef science and policy officer at the Conservation Biology Institute, a nonprofit science group, told CNN that the changes should be seen as a way of "transforming things that we have found stressful" instead of "sacrifices".
On Monday, US Secretary of State Mike Pompeo said in a statement that the official withdrawal notifications had been sent to the United Nations.
"Today we begin the formal process of withdrawing from the Paris Agreement," he later wrote on Twitter. "The US is proud of our record as a world leader in reducing all emissions, fostering resilience, growing our economy, and ensuring energy for our citizens."
President Donald Trump, who has described climate change as a "hoax", had promised to leave the treaty when he was a candidate for the White House. The announcement on Monday means the US will officially leave the pact on Nov 4, 2020, and if it were to re-enter, there would be a 30-day waiting period.
"I was concerned that we are now making the environment a political issue, and the environment should not be seen as a partisan issue," Leslie Duram, a professor of geography and environmental resources at Southern Illinois University in Carbondale, told NBC News. "I want us all to realize that we, as human beings and inhabitants of this planet, need to come together to take action to help preserve the environment."
As the second-largest producer of greenhouse gases, the US now is the only country that has quit the 2015 Paris Agreement, a global effort to combat climate change ushered in during the Obama administration. Former President Barack Obama had previously pledged to cut emissions by 26 to 28 percent by 2025.
In another report titled "The Truth Behind the Climate Pledges", published by the Universal Ecological Fund on Tuesday, researchers also warned that of the 184 countries and regions that signed the pact, only 36 were deemed significant of cutting emissions by 40 percent by 2030.
Another 12 countries were considered partially sufficient in meeting the goal of cutting emissions between 20 to 40 percent by 2030.
"With few exceptions, the pledges of rich, middle-income and poor nations are insufficient to address climate change," said Robert Watson, co-author of the report and former chair of the Intergovernmental Panel on Climate Change. "Simply, the pledges are far too little, too late."
Watson also said that the EU "is clearly in the lead in trying to address the climate crisis" after it committed to cutting greenhouse gas emissions by 40 percent by 2030.
Last month was the hottest October ever recorded globally, according to the European Union's Copernicus Climate Change Service, an organization that analyzes global temperatures.
