Recently, the US released its analysis of the country's 2014 carbon emissions. It showed that while carbon emissions are still growing, their growth has slowed even as economic activity expanded. A new report indicates the same held true globally. Even though the global economy expanded by three percent last year, carbon emissions only rose by half a percent. The report raises the hope that we've partly decoupled economic growth and carbon emissions.

The analysis was performed by the Netherlands Environmental Assessment Agency in cooperation with the European Commission's Joint Research Center. It gathered statistics on energy use from governments, NGOs, and the energy industry to compile numbers on the energy economy and its carbon emissions.

In past years, the news was pretty grim. For roughly a decade, emissions were rising at about four percent a year, bringing CO 2 levels up to 400 parts-per-million earlier this year for the first time in millions of years. But earlier in this decade, the growth rate dropped to one percent a year for a couple of years. At the time, it wasn't clear whether this was a momentary blip or indicative of a long-term change.

The 2014 figures show growth of only half a percent, making it three years straight with declining carbon emissions. Since this came during a period of economic expansion, it's made the report's authors optimistic: "the world’s economy grew by three percent, showing a partial decoupling between the growth in global CO2 emissions and that in the economy." It also came as the total generation of power increased by 1.5 percent, suggesting we're starting to decouple power and carbon emissions as well. The explanation for that is simple: two-thirds of the global increase in power generation came from renewable sources.

That's not to say everything is rosy. Since there was still growth, carbon emissions went up to a new record of 35.7 billion tonnes. And a per-capita decline in energy use was largely driven by the planet's record warmth, which significantly cut the need for winter heating throughout Europe and elsewhere (though certainly not in most of the US).

New sources

A decade ago, wind and solar only generated a small fraction of the power used around the globe. But the two have been doubling every four years and are now up to four percent. Hydropower accounts for another 16.5 percent of the power generation, and sources like biomass and geothermal take renewables' share up to 22.5 percent of the global power generation (a new record). Hydropower use dropped very slightly last year (down 3.7 percent), while wind and solar rose by 13 percent.

Investments in new renewable power were twice as large as the money spent to develop fossil fuel capacity last year. Capacity-wise, wind power went up by 16 percent last year, reaching 370GW globally. Collectively, that generated over 700 TeraWatt-hours last year. The report notes that, in many regions, unsubsidized wind power is not cost-competitive with fossil fuel sources.

Solar is still well behind, with photovoltaics generating a bit under 200 TW-hr last year. It's still not competitive with fossil fuels, but the levelized cost of photovoltaics has been cut in half in the last four years. Spurred by those falling costs, the capacity has increased from 2.6GW to 177GW over the last decade with nearly 30 percent growth last year alone.

The last major source of low-carbon energy is nuclear. Here, the story's been mixed. A number of countries are seeing significant new construction—China's building 26 new reactors, Russia another 10, and India, the US, and Korea have 16 in the works among them. But since the 1990s, new construction has only managed to offset the closure of older plants.

Even though the number of plants has remained roughly constant for over a decade, the share of nuclear power has dropped from a high of 17 percent down to about 11 percent over the last decade. That drop is largely a product of the Fukushima disaster, which idled a large number of plants in Japan. And despite China adding the equivalent of the entire Belgian nuclear fleet last year, it still left nuclear generating only a bit over two percent of the country's power last year. Wind, for comparison, was at 2.8 percent of China's electricity supply.

Regional differences

China's coal numbers China recently made a major revision to the numbers it provides on the amount of coal it has used. Those revisions raise the coal burning of most of the years of the last decade by anywhere from seven to 13 percent. That in turn raises its emissions by between six and 11 percent. Since China is such a large source of emissions, the entire global numbers have gone up by a few percent. In terms of the carbon budget we are limited to if we want to keep warming under two percent, it shifts the 2050 targets by two months. In other words, we now need to be at 2050 emissions levels two months earlier than we would have otherwise.

What happens in China now has an outsized impact on global carbon emissions. It was only a decade ago that China passed the US in terms of being the largest source of greenhouse gases. Now, the country emits nearly a third of the global volume. The US is responsible for another 15 percent, the EU is at 10 percent, and India is at 6.5 percent.

That said, China is changing. Its increase in carbon dioxide emissions last year was only 0.9 percent—the same as the US. And coal demand in the country was completely flat last year. This has come about largely because of the growth of a service economy within China. Within the past three years, services displaced industry as the largest contributor to the country's GDP, and they are rapidly approaching the point where they'd account for half of the economy. (In the US and EU, services are nearly 80 percent of the economy.)

Of course, in per-capita terms, China's emissions make it look like a European country, but it won't stay that way for long. EU emissions dropped by 5.4 percent last year, largely driven by a drop in fossil fuel consumption. Only 10 percent of that drop is estimated to come from the continent's mild winter, so there are larger structural changes going on. EU emissions per capita remain roughly half those of the US, where emissions rose slightly.

The EU wasn't alone in dropping its emissions. Japan's dropped by 2.6 percent, despite the continued idling of most of its nuclear plants. Australia saw a two percent reduction, although its per-capita emissions remain about as bad as the US.

The real concerns, however, are the steep rises in a number of rapidly developing economies. India saw its carbon emissions go up by nearly eight percent, part of an acceleration that started early in this century. Brazil, once the champion of biofuels, saw a 3.3 percent increase; Indonesia experienced 3.2 percent.

So overall the 2014 report is a mixed bag. There are causes for optimism scattered within it—the EU's large drop in emissions, the changes taking place in China, and the general decoupling between economic growth and carbon emissions. But emissions are still going up, and there are a number of growing economies that appear ready to take China's place as engines of emissions growth.