The biggest difference in the new report is that new technologies considered high-tech solutions to climate change now play a much smaller role than expected in 2021. These technologies, including hydrogen fuel cells for heavy vehicles and devices that filter carbon dioxide emissions from Cigarettes or ambient air now account for 35% of emissions reductions, up from about 50%.

Why? The report shows that they simply did not meet expectations.

“I think some reality is starting to set in, and I wonder how the reality of this report will play out in these areas,” said Dave Jones, who directs energy analysis at the Ember Center for Global Insights.

“Currently, hydrogen production is more of a climate problem than a climate solution,” the report says. Hydrogen as a fuel is not new, but it is still produced mainly from gas. Many countries, including the United States, are investing to make hydrogen more sustainable by using fossil fuels with renewable energy or carbon sequestration. If successful, this project could produce environmentally friendly fuel for planes, ships or trucks.

But building the infrastructure needed to transport hydrogen poses a bigger hurdle than expected, Jones said. On the other hand, even if electric charging infrastructures are still limited, they are developing more rapidly. The IEA's updated 2050 roadmap reduces the share of heavy fuel cell electric vehicles in 2050 compared to the initial forecast for 2021.

The roadmap also reduces the role of carbon capture technology in reducing power plant emissions by about 40%. “The story [on carbon sequestration] so far has been one of unmet expectations,” says the new IEA report. The U.S. Department of Energy (DOE) wasted tens of millions of dollars on carbon capture projects that failed “for reasons that affected the economic viability of the projects,” according to a 2021 Government Accountability Office report.

“Removing carbon from the atmosphere is very expensive. We have to do everything we can to deprioritize this,” Fatih Biral, executive director of the International Energy Agency, said in a press release. If pollution does not fall quickly and global temperatures rise At more than 1.5 degrees, many countries would need to dive carbon-dive to try to get rid of this heating. They could try using “expensive and unproven” capture technology. But relying on this technology would lead to higher climate risks.

The report says global renewable energy capacity must triple by 2030 to end pollution caused by global warming. Clean energy spending will double from $1.8 trillion this year to $4.5 trillion by the beginning of the next decade. Energy efficiency must also double in the same period, and the world's richest countries must reach net zero emissions by the global target of 2050.

The timing of updating this roadmap is critical. This report builds on the first UN global report on how countries are responding to climate change. In short, they are falling behind as emissions continue to rise despite the need to limit temperature rises to 1.5 degrees.

Last week, the United Nations held a climate summit in New York to pressure countries to increase their commitments to clean energy, but the leaders of the countries with the largest carbon footprint, China and the United States, did not attend. They will get another chance at the broader UN climate conference starting in November in Dubai.