Worst global warming predictions likely the most accurate, study finds

What you know about climate change is correct — for the most part.

The worst-case predictions regarding the effects of global warming are the most likely to be true, a new study published this week has warned.

"Our study indicates that if emissions follow a commonly used business-as-usual scenario, there is a 93 per cent chance that global warming will exceed 4°C by the end of this century," Dr. Ken Caldeira, an atmospheric scientist at the Carnegie Institution for Science, who co-authored the study told The Independent.

This research shows a dramatic increase over previous estimates, which placed the likelihood of such a drastic increase at just 62 percent.

Since the Earth's climate system is incredibly complex, different scientists have put forward different models to determine how fast the planet is warming. This has resulted in a range of predictions, some more dire than others.

The new study, published in the academic journal "Nature", aimed to determine whether the upper or lower-end estimates are more reliable.

Caldeira and co-author Dr. Patrick Brown looked at models that proved to be the best at simulating climate patterns in the recent past. They reasoned that these models would present the most accurate estimates.

"It makes sense that the models that do the best job at simulating today's observations might be the models with the most reliable predictions," Caldeira explained.

According to the researchers' conclusions, models with higher estimates are more likely to be accurate, meaning the degree of warming is likely 0.5°C higher than previously accepted.

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Credit: AP Photo/Andy Wong, File

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Credit: AP Photo/Andy Wong, File

Scientist that weren't involved with the research have come out in support of the findings as well.

"There have been many previous studies trying to compare climate models with measurements of past surface-temperature, but these have not proved very conclusive in reducing the uncertainty in the range of future temperature projections," Professor William Collins, a meteorologist at the University of Reading, said.

Professor Collins explained that the new study "breaks the issue down into the fundamental building blocks of climate change."

While the overwhelming majority of climatologists and environmental scientists agree that climate change is a problem accelerated by human activity, representatives from the fossil fuel industry and the administration of U.S. President Donald Trump have dismissed such claims.

However, with more and more research backing worst-case predictions, complete dismissal of such findings becomes increasingly difficult. This study in particular addresses one key point climate change deniers often seize upon: the uncertainty that comes with so many different climate models.

"This study undermines that logic," Dr. Brown told MIT Technology Review. "There are problems with climate models, but the ones that are most accurate are the ones that produce the most warming in the future."

Dr. Brown and Dr. Cadeira's study also comes on the heels of a dire warning issued by more than 15,000 scientists from around the world last month. The scientists warned that quick and drastic actions should be undertaken by society to address the threat to Earth.

"Soon it will be too late to shift course away from our failing trajectory, and time is running out," scientists wrote in the letter. "We must recognize, in our day-to-day lives and in our governing institutions, that Earth with all its life is our only home."

But despite scientists around the world, including the leading minds in climate and environmental research, raising their voices in concern, President Donald Trump's administration has expressed its disinterest and disbelief.

President Donald Trump said in June that he would pull the U.S. out of the landmark 2015 Paris climate agreement, joining only two other nations – Syria and Nicaragua – which had not signed the international accord.

Since then, Nicaragua agreed to sign the agreement in October, and Syria followed in November.

Instead of addressing greenhouse gas emissions as the Paris accord requires, the White House said it "will promote coal, natural gas and nuclear energy as an answer to climate change," a decision scientists around the globe have warned against.