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Can global warming be halted?

The Carr wildfire ravaged parts of California in 2018.The Carr wildfire ravaged parts of California in 2018.Global warming has become an urgent issue. The Intergovernmental Panel on Climate Change (IPCC) has warned of serious consequences for the planet if global average temperature rises by more than 1.5°C (2.5°F) above pre-industrial levels (those recorded in 1750, before the Industrial Revolution). This may not seem very much at all, but the increase that has already occurred—about 1°C—is having a major impact, with torrential storms, heatwaves and wildfires becoming much more frequent. The higher temperatures climb, the greater the risk of polar ice sheets melting. This would trigger a sea level rise of several metres, enough to flood many densely populated coastal regions across the world. Scientists fear that a "tipping point" will be reached when global warming starts to accelerate of its own accord. We know beyond doubt that human activity, through the rapid increase in carbon dioxide emissions, is the cause of global warming. What, then, can we do to halt it?

 

Greenhouse gases

Emissions that add to greenhouse gasesEmissions that add to greenhouse gasesCoal-fired power station, MinnesotaCoal-fired power station, Minnesota
Certain gases in the atmosphere, such as carbon dioxide (CO2) and methane, prevent some of the Sun's heat from radiating back into space, warming the planet's surface. They are known as greenhouse gases, because they act in a similar way to the glass in a garden greenhouse, keeping it warm inside. In fact natural levels of greenhouse gases are essential to life on Earth. If they were not present, our planet would have an average temperature of -30°C (-22°F).

Some scientists estimate that if emissions of carbon dioxide are limited to no more than 420 billion tonnes this century, we will have around a 70% chance of keeping global warming down to around 1.5°C. Since a total of 42 billion tonnes of carbon dioxide was emitted in a single year (2017) alone, we have only 10 years to get emissions down to net zero.

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