Scientists thought carbon emissions had peaked. They’ve never been higher.

Near the end of 2020, as the covid-19 pandemic continued to rage, a few climate scientists and energy experts made a prediction. They estimated that emissions from fossil fuels - which had just plummeted thanks to the global pandemic - might never again reach the heights of 2019. Perhaps, they speculated, after over a century of ever more carbon dioxide flowing into the atmosphere, the world had finally reached “peak” emissions.

They were wrong.

According to a report released last month by the Global Carbon Project, carbon emissions from fossil fuels in 2022 are expected to reach 37.5 billion tons of carbon dioxide, the highest ever recorded. That means that despite the continued fallout from the coronavirus pandemic - which caused emissions to drop by over 5 percent in 2020 - CO2 emissions are back and stronger than ever.

Scientists have reacted with dismay. For years before the pandemic, emissions appeared to be leveling off - sparking hope that the world was finally reaching the moment when emissions would start to come down. Then in 2020, “Covid came, there was a huge drop in emissions - and I guess we got a little overexcited,” said Glen Peters, a climate scientist at the Center for International Climate Research in Oslo.

Here’s why researchers were wrong about emissions peaking - and what it means for the future - in three charts:

1. History repeats itself

For the past century, carbon emissions have only ever fallen in one circumstance: crisis. When the 2008-2009 global financial crisis rocked the world’s economic system, carbon emissions dropped by 1.4 percent. When the oil crises of 1973 and 1979 destabilized economies and caused people to wait in long lines for gasoline, emissions - previously on a steep upward climb - sputtered to a halt. And when the coronavirus pandemic locked billions of people indoors, the CO2 spilling into the atmosphere dropped by 5.2 percent - a record only matched by the aftermath of World War II.

Economic crisis, of course, is not the way that nations want to cut their carbon emissions. And in all of these historical examples, the temporary drop in emissions didn’t last long. After the financial crisis, emissions rebounded, growing by approximately 1.65 billion tons in a single year.

In the immediate aftermath of the pandemic, some experts thought the world would take a different tack. Countries vowed to “build back better” and inject clean energy spending into their stimulus packages. But the result was not as green as might have been hoped. According to one analysis, only 6 percent of the stimulus money spent by G-20 nations went to areas that could cut emissions. And as people returned to flying, driving and making stuff, emissions bounced back.

2. Coal, coal, coal

For most of this century, the story of climate change has also been a story of coal. Coal is the world’s dirtiest fossil fuel, releasing 820 metric tons of greenhouse gas emissions for every gigawatt of electricity produced. (Solar power, in contrast, releases about five metric tons for every gigawatt of electricity produced.)

Before the pandemic, coal looked set for a long decline - which was part of why scientists and experts thought emissions might have reached their peak. But in the past couple of years, coal has made a resurgence. Russia’s invasion of Ukraine has raised natural gas prices around the world, causing some European countries to lean more heavily on coal to keep energy prices low.

Thanks to China’s continued pandemic lockdowns, the world’s largest economy hasn’t accelerated its coal use quite as much as it could have - but India’s use of the world’s dirtiest fuel has skyrocketed. India’s coal use is set to increase by 5 percent in 2022, on top of a 15 percent increase the year before. All of that means that in the past two years, emissions from burning coal have increased by almost a gigaton.

3. Developed versus developing countries

Part of the issue is that, while developed countries have seen their emissions decline over the past decades, that decline hasn’t happened nearly fast enough to counterbalance the growth in emissions from developing countries. China’s emissions have skyrocketed over the past 20 years, as the country has developed and lifted millions out of poverty. (Despite its high overall emissions, though, China still has lower per capita carbon emissions than the United States.) India’s emissions are growing more slowly, but still growing.

“Fossil fuels are still the cheapest way to provide reliable electricity,” said Ken Caldeira, a climate scientist at the Carnegie Institution for Science. (While wind and solar can be cheaper than fossil fuels in some cases, their intermittency - and the absence of cheap, big batteries - mean that it’s difficult to build an entire electricity system out of just renewable energy.) “It’s like Maslow’s hierarchy of needs,” Caldeira said. “Developing countries have to put climate concerns second to their economic concerns.”

For emissions to peak, therefore, richer countries would either need to cut their emissions much more rapidly - or assist developing countries to switch to lower-carbon fuel sources. And the latter option doesn’t look particularly good. Conflicts over flows of money from richer to poorer countries have haunted the U.N. climate negotiation process for years, despite recent small victories at COP27.

“We’ve been unwilling to subsidize a massive green energy transition for ourselves,” Caldeira said. “And the idea that then we’re going to subsidize that for the Global South seems a little implausible.”