Atmospheric CO2 Levels Flatten for Second Straight Year

For the second year in a row, energy-related carbon dioxide emissions (CO2) – the largest source of man-made greenhouse gas emissions – have stayed flat, according to an analysis of 2015 preliminary data released last week by the International Energy Agency (IEA).

That doesn’t mean global warming is slowing, however. Despite the cutbacks in industrial production of the gas, the amount of CO2 in the atmosphere has continued to grow as drought and erratic rainfall meant that the earth was unable to sequester more of the gas, according to the US National Oceanic and Atmospheric Administration, which showed that 2015 was the hottest year on record. Temperatures are continuing to rise inexorably, with January the hottest on record for the month. An alarming new study by Dartmouth College has also confirmed that warmer, wetter conditions in the Arctic are accelerating the loss of carbon stored in tundra and permafrost soils, creating a potential positive feedback that is expected to further boost global temperatures.

Nonetheless, “The new figures confirm last year’s surprising but welcome news: we now have seen two straight years of greenhouse gas emissions decoupling from economic growth,” said IEA Executive Director Fatih Birol in a prepared release. “Coming just a few months after the landmark COP21 agreement in Paris, this is yet another boost to the global fight against climate change.”


Global emissions of carbon dioxide stood at 32.1 billion tonnes in 2015, having remained essentially flat since 2013, the report said.

Nonetheless, the level at which renewables is taking over energy production is surprising. Preliminary data provided by the IEA suggest that renewables accounted for 90 percent of new electricity generation in 2015. Wind alone produced more than half of new electricity generation. In parallel, the global economy continued to grow by more than 3 percent, offering further evidence that the link between economic growth and emissions growth is weakening.

“In the more than 40 years in which the IEA has been providing information on CO2 emissions, there have been only four periods in which emissions stood still or fell compared to the previous year. According to the report, three of those – the early 1980s, 1992 and 2009 – were associated with global economic weakness. But the recent stall in emissions comes amid economic expansion: according to the International Monetary Fund, global GDP grew by 3.4 percent in 2014 and 3.1 percent in 2015.

The two largest emitters, China and the United States, both registered a decline in energy-related CO2 in 2015. In China, emissions declined by 1.5 percent, as coal use dropped for the second year in a row.

“The economic restructuring towards less energy-intensive industries and the government’s efforts to decarbonize electricity generation pushed coal use down, the report indicated. “In 2015, coal generated less than 70 percent of Chinese electricity, 10 percentage points less than four years ago (in 2011). Over the same period, low-carbon sources jumped from 19 percent to 28 percent, with hydro and wind accounting for most of the increase. In the United States, emissions declined by 2 percent, as a large switch from coal to natural gas use in electricity generation took place.

Despite the decline on the part of China and the United States, however, that was offset by increasing emissions in most other Asian developing economies and the Middle East, and also a moderate increase in Europe.

More details on the data and analysis will be included in a World Energy Outlook special report on energy and air quality that will be released at the end of June. The report will go beyond CO2 emissions and will provide a first in-depth analysis of the role the energy sector plays in air pollution, a crucial policy issue that today results in 7 million premature deaths a year. The report will provide the outlook for emissions and their impact on health, and provide policy makers with strategies to mitigate energy-related air pollution in the short and long term.