Advocates of combating climate change are increasingly invoking doomsday scenarios to pressure President Biden to take unilateral action to lower greenhouse gas emissions, despite a history of such claims falling flat. 

The rhetoric is coming not only from progressive activists but also Democrats on Capitol Hill. Lawmakers, in particular, have intensified their doomsday predictions as hopes for a climate change deal have waned within the Senate in recent days. 

Sen. Bernie Sanders, I-Vt., recently told supporters that if immediate action was not taken on climate change, an immigration and public health crisis was likely to appear by 2030.

CLIMATE ACTIVISTS EMBRACE EXTREME TACTICS, VIOLENCE AS DEADLINE TO 'SAVE THE PLANET' DRAWS NEAR

"Thousands of people are dying," said Sanders. "You’re going to see more mass migrations, more diseases … For the sake of future generations, our kids, our grandchildren, we have got to act." 

Concordia University echoed a similar message when publicizing its Climate Clock. Launched in 2020 to give world leaders a sense of urgency, the clock purports to denote the amount of time humanity has left to address climate change to avoid the most dangerous consequences of global warming. 

At the moment, that figure stands at just under seven years. Activists say that is time left to avert disaster by limiting global warming to 1.5 degrees Celsius. 

In 2019, Rep. Alexandria Ocasio-Cortez suggested the humanity would be done by 2031. 

"Millennials and people, you know, Gen Z and all these folks that will come after us are looking up and we’re like: ‘The world is gonna end in 12 years if we don’t address climate change and your biggest issue is how are we gonna pay for it?’" she said.

Critics note that the doom and gloom is nothing new. They say it's part of a long-running strategy that sees proponents of combating climate change lay out alarming predictions of global catastrophe.

"People have been proclaiming the end of the world since forever. All have been wrong," said Steve Milloy, who advised President Donald Trump on staffing the Environmental Protection Agency after the 2016 election. "They make these End Times predictions for a variety of reasons ranging from ignorance to politics to personal aggrandizement." 

Some point to former Vice President Al Gore as the poster boy for the strategy. Gore has made millions and won a Nobel Peace Prize for his climate change activism. 

But some of his major predictions have failed to become reality.

CLIMATE ACTIVISTS EXPAND TIRE-SLASHING OPERATION BEYOND NYC. HERE ARE THE CITIES THEY'VE HIT

In 2006, Gore told audiences while marketing his documentary, "An Inconvenient Truth," that the world would reach a point of no return in ten years if the global economy did not transition away from fossil fuels. Likewise, Gore in 2009 cited evidence suggesting that there was a 75% chance that by 2013, the North Pole would start becoming "ice-free" for a portion of the summer.

Some experts say the reason why such predictions prove faulty, even when backed up by scientific studies, is because it's difficult to gauge the economic and social impact of changes in temperature. 

"It's incredibly difficult to translate temperature increases into changing weather effects using predictive models," said Myron Ebell, the director of the Competitive Enterprise Institute’s center for energy and environment. "Most of the time the data doesn't line up or scientists assume a larger temperature increase will happen than actually does and that skews the entire prediction."

Critics say that studies trying to analyze the impact of changes in temperature rely heavily on correlations, rather than causes

Doomsday predictions have only increased as climate legislation on Capitol Hill has stalled because of Democratic infighting. 

Last week, 60 House Democrats echoed the message when calling on Biden to declare a national emergency on climate change. The move would allow the White House to mobilize emergency powers to lower carbon emissions. 

"If we don’t really begin to lower emissions, this planet has no chance," Rep. Alan Lowenthal, D-Calif, said recently. "We have a few years left and that’s it. The planet is dying." 

Democrats have also tried to capitalize on the recent heatwave besieging the East Coast as proof that climate change is getting worse and dire action is needed. 

Milloy says such tactics ignore broader trends and data when it comes to the climate. 

"Climate alarmists are trying to surf a heat wave to pressure Joe Biden into declaring a climate emergency," he said.