

A United Nations scientific body just released a seminal report on how the world’s energy systems would have to be transformed to adequately address climate change.
The big picture: The world is still heavily dependent upon fossil fuels. It accounts for 81% of the world's energy consumption, a figure that hasn’t changed in 30 years. Evolving electricity mixes is one clear gauge of how countries are doing cutting their greenhouse gas emissions and using cleaner energy technologies.
The details: Four countries — United States, Japan, China and Denmark — illustrate the challenges different parts of the world have in greening their electricity mixes. You can hover over the Denmark graphic to pull up the same info for any other country.
- The United States' greenhouse gas emissions are at lows not seen in decades, thanks largely to cleaner-burning natural gas displacing the far dirtier coal, along with an increase in renewables. While the U.S. is a leader in cutting its emissions, President Trump wants to withdraw America from the Paris climate deal and bring back coal, which would increase domestic emissions.
- Japan is a case study of what is likely to happen today when a lot of carbon-free electricity goes away. After the country shut down its nuclear power plants in response to the 2011 Fukushima disaster, its dependence on fossil fuels — and natural gas in particular — increased.
- China is ground zero for all things energy and climate change given its population size and energy appetite. Its dependence on coal is huge, yet it’s also leading in developing renewable energy. Its second-largest source of electricity is actually hydropower, a renewable energy that doesn’t get as much attention today as wind and solar.
- Denmark is a prime example of the potential for wind energy, particularly offshore. The renewable energy provides nearly 50% of the country’s electricity, a huge growth just over the last couple of decades.
Go deeper: UN details massive changes needed to slow global warming