The numbers don't add up if the world is to have an even chance of limiting the global average temperature increase to 1.5 °C above where it stood at the start of the Industrial Revolution.

That's according to a major new 224-page report by the International Energy Agency.

In Net Zero by 2050: a Roadmap for the Global Energy Sector, the IEA points out that even if all governments' climate promised are kept, there's little chance of achieving the goals of the 2015 Paris Agreement.

However, there's still a "viable pathway" toward net-zero emissions by 2050, it notes.

"The scale and speed of the efforts demanded by this critical and formidable goal—our best chance of tackling climate change and limiting global warming to 1.5 °C—make this perhaps the greatest challenge humankind has ever faced,” IEA executive director Fatih Barol said in a news release.

“The IEA’s pathway to this brighter future brings a historic surge in clean energy investment that creates millions of new jobs and lifts global economic growth," he continued. "Moving the world onto that pathway requires strong and credible policy actions from governments, underpinned by much greater international cooperation.” 

This would require annual additions of 630 gigawatts of solar photovoltaic power and 390 gigawatts of wind power by 2030.

About US$40 billion per year would be required to provide electricity to 785 million people who don't have it now, as well as clean cooking solutions to 2.6 billion people.

“The pathway laid out in our Roadmap is global in scope, but each country will need to design its own strategy, taking into account its own specific circumstances,” Birol said. “Plans need to reflect countries’ differing stages of economic development: in our pathway, advanced economies reach net zero before developing economies."

Stated policies scenario offers bleak outlook

The report forecasts global electricity demand to increase by 80 percent between 2020 and 2050 in the "stated policies scenario" announced by governments. That's double the anticipated rate of growth in final energy consumption.

"Annual energy‐related and industrial process CO2 emissions rise from 34 Gt in 2020 to 36 Gt in 2030 and remain around this level until 2050," the report concludes under the stated policies scenario.

"If emissions continue on this trajectory, with similar changes in non-energy-related GHG emissions, this would lead to a temperature rise of around 2.7 °C by 2100 (with a 50% probability)," it continues. "Renewables provide almost 55% of global electricity generation in 2050 (up from 29% in 2020), but clean energy transitions lag in other sectors. Global coal use falls by 15% between 2020 and 2050; oil use in 2050 is 15% higher than in 2020; and natural gas use is almost 50% higher."

The "announced pledges case", on the other hand, assumes that all national net-zero pledges are achieved in full and on time.

That would increase the share of renewables to 70 percent by 2050 with oil demand falling about 10 percent from 2020 to 80 million barrels per day by 2050. Coal use would decline 50 percent over the same period and natural gas use would expand by 10 percent.

This led the IEA to conclude that even the announced pledges case "starkly highlights that existing net zero pledges, even if delivered in full, fall well short of what's necessary to reach global net-zero emissions by 2050".

Feedback loops create additional risk

If temperature increases aren't contained, that elevates the chances of climate feedback loops kicking in, setting the conditions for dramatic increases in the future.

Those feedback loops include the melting of ice in the Arctic and Antarctic and on Greenland, disruptions to the jet stream and thermohaline circulation in the Atlantic Ocean, and melting of permafrost and of alpine glaciers, including in the Himalayas, which provide water to more than two billion people.

The U.S. Geological Survey notes on its website that increasing global surface temperatures heighten the possibility of droughts and damaging storms.

"As more water vapor is evaporated into the atmosphere it becomes fuel for more powerful storms to develop," it states. "More heat in the atmosphere and warmer ocean surface temperatures can lead to increased wind speeds in tropical storms. Rising sea levels expose higher locations not usually subjected to the power of the sea and to the erosive forces of waves and currents."

Canada is a member of the IEA. Among the report's peer reviewers were Todd Litman, who heads the Victoria Transport Policy Institute, and Amanda Wilson of Natural Resources Canada.