PART TWO The planet's climate has constantly been changing over thousands of years. The global average temperature today is about 15°C. Scientists are worried that the planet is warming faster than ever before. The 20 warmest years on record have been in the past 22 years, according to the World Meteorological Organization. If this trend continues, temperatures may rise by 3-5°C by 2100. Scientists say we should try and stop this trend and not allow the average global temperature to rise more than 1.5° C, let alone a 2°C rise which would be pretty bad for us all. Now, half a degree doesn't sound like much - but it could make a big difference to the planet. A 2°C rise would mean that all the coral reefs would disappear, but a 1.5°C rise means that there would still be some. Also, 18 per cent of the insects on Earth will disappear if the temperature goes up by 2°C, compared to 6 per cent disappearing at 1.5°C. Thirty-seven per cent of people will be affected by dangerous heatwaves at 2°C rise. That's twice the number compared to at a 1.5°C rise. Whether it's coral reefs, crops, floods or the survival of species, scientists say everyone and everything is far better off in a world that limits the rise to 1.5°C. So, what can we do
