In 2015, nearly 200 governments promised to try to stop global warming at 1.5 degrees Celsius (2.7°F) by the end of the century. But seven years later, as they meet again for a climate summit in Egypt, they are pursuing policies that will heat the planet by almost double that.

For world leaders to honor their promises, they must sharply cut the amount of planet-heating gas humanity pumps into the air each year. Greenhouse gas emissions would have to fall 45% by the end of the decade and reach net-zero by 2050. A key driver of that titanic shift would be making electricity cleanly, instead of with fossil fuels, and electrifying activities that involve burning coal, oil and gas.

Here's where the world stands in building infrastructure to make clean electricity.

Most electricity is made from coal, the dirtiest source of energy, and fossil gas, which is cleaner but still polluting. Burning these fuels releases gases that act like a greenhouse around the Earth, heating the planet and making extreme weather worse.

Just under 40% of the world's electricity comes from low-carbon sources like solar, wind, nuclear and hydropower.

The share of renewable energy in the global electricity mix has risen rapidly in the last decade, while the share of nuclear has fallen. The amount of fossil fuels in the mix has remained steady.

Total demand for electricity has nearly doubled in the last two decades. In countries where living standards have risen rapidly, like China and India, people have burned more coal as governments have connected people in rural towns and sprawling megacities to electricity grids for the first time. In rich countries where electricity has grown cleaner, like the US and parts of Europe, people have swapped from coal to gas as the main source of electricity.

Renewable energy sources like solar, wind and hydropower now make up about a quarter of the world's electricity.

The rise of renewable energy is set to speed up. As manufacturers have built more solar panels and wind turbines, the technologies have improved and the industry has become more efficient, making them cheap and easy to build. The costs of making electricity from sunlight or wind have fallen sharply enough to make them competitive with fossil fuels. In most of the world, building a new solar farm is now cheaper than keeping an existing coal plant running, let alone building new ones.

 

The calculations do not include the costs of storing electricity on cloudy days with little wind, or account for the health costs of breathing dirty air from burning fossil fuels.

Spending on clean energy is expected to hit $1.4 trillion (€1.4 trillion) in 2022, according to the International Energy Agency, a Paris-based organization led by the energy ministers of mostly rich countries. But almost all the growth is in rich countries and China, where the costs of financing new infrastructure are lower. Middle-income countries must spend more than twice as much paying off debt, and struggle to get loans for projects. In sub-Saharan Africa, where 600 million people do not have access to electricity, finance is particularly hard to come by.

Rich countries promised poor ones $100 billion a year in finance by 2020 to cut their emissions and adapt to a hotter world. They broke their promise. The latest estimates show they raised $83 billion of public and private finance in 2020.

 

The share of low-carbon energy is growing. But it would have to rise six times faster than historical rates to put the world on track to keep global warming to 1.5 C, according to a report published in late October by two environmental research groups, Climate Action Tracker and the World Resources Institute. 

Fossil fuels are projected to peak this decade, the International Energy Agency announced at the end of October. To cut emissions quickly enough for world leaders to honor their promises, electricity grids would have to become twice as clean by the end of the decade. In rich countries, they would have to hit net zero by 2035 – compensating for remaining emissions by sucking carbon out of the atmosphere – and in the rest of the world by 2040.

A previous version of the legend in the third graphic mislabeled offshore and onshore wind energy. This has been corrected.