Category: Climate change

Emissions by sector 2010

Emissions by category

Which activities and sectors produce the most greenhouse gas (GHG) emissions? The graph above shows us that they do not necessarily come from the places we might think. With a quarter of all emissions, agriculture and forestry is perhaps the biggest surprise. We tend to think of GHGs as coming from combustion of fossil fuels, in cars, furnaces and coal-fired power plants.  But high meat and dairy consumption are two of the main drivers of agricultural emissions, and makes this sector a potent threat — not least because it’s not obvious.

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CO2 emissions 1990-2017

Emissions up in 2017

After declining in 2016, CO2 emissions went back up in 2017. According to estimates from the Global Carbon Project, emissions increased by almost 600 million tonnes, ending up at 41.47 billion tonnes. Emissions had actually decreased in 2016 after flattening out over the last few years, bringing hope that we had finally reached peak carbon pollution, but it was not to be. Still, emissions have only edged up slightly in five years, so there is hope that the curve will finally start to bend downwards. Just as the curve had flattened mostly because of decreasing coal use in China, the Middle Kingdom was also responsible for the increase, with emissions going up by 3.5%, including 3% growth in coal emissions. China has promised to peak its emissions before 2030, but not quite yet it seems. Let’s hope they do it soon.

Source: The Global Carbon Budget 2017, Le Quéré et al., 2017, pp.33-34 (open access)

The global carbon budget 2018

The Carbon Budget — Living Beyond Our Means

There are good reasons to calculate our carbon budget. The carbon pie shows how much CO2 we’ve got to play with, how much we’ve used and how fast we’re using it. This isn’t a license to pollute, but the opposite. As long as we didn’t have a very good idea how much carbon we could emit, it was easier for polluters to run away from the problem or push it ahead of them. The carbon pie should be a visceral reminder of how urgent the problem has become and it should compel governments to reflect on what they all need to do to avoid overshooting. The small remaining carbon space no longer allows anyone to continue with business-as-usual.

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Arctic banner

Tipping points in the Arctic

When the summer melting season ended in 2007, the icecap floating in the ocean over the North Pole had shrunk to its smallest size ever recorded. More than one-and-a-half million square kilometres that had been covered with ice the year before was open ocean. According to satellite data, the remaining summer sea ice measured almost forty per cent less than the average for the period of 1979 to 2000. The event was a serious confirmation that had been suspected for a while in the scientific community: that the Earth may be prone to abrupt climate change and tipping points. The science of non-linear change is challenging our notions of what climate change is and when it will occur—and it is utterly alarming.

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Earth burning

Catastropic or abrupt climate change

We tend to think of climate change as something that happens very slowly, over a very long time. We further tend to think that its more serious effects are still decades away. We are learning now that both assumptions are wrong. While scientists are getting a firmer understanding of how the climate works and how sudden and self-sustaining climatic changes can be triggered, it is becoming clear that climate change is in fact not decades away. For many, it is already here.

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