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Causes: Would the climate be warming without humans?

Would the climate be warming without humans?

Image: Joseph Chan

Would the climate be warming without humans?

 Summary

  • In the 4.54 billion years since Earth formed, natural climate factors or forcings have changed Earth’s climate many times.
  • Today, when all natural forcings are added together, Earth should be cooling. Instead, we’re warming rapidly (Figs. 1 & 2).
  • We know from fundamental laws of physics that greenhouse gasses trap heat in the atmosphere. We know we’re emitting lots of them (Video 2) and that’s changing the chemistry of the atmosphere and making it warmer.
  • Any alternative opinion would need to explain not only why global temperatures are rising instead of falling (Figs. 1 & 2), and also why the laws of physics and chemistry have stopped working.
  • The good news is that we can use nature to capture and store excess greenhouse gasses in back the ground, so we can limit the impacts.

Maybe the weather is erratic, but that’s happened before, right? In fact, the nice weather we’ve had for the last 4,500 years allowed us to build a global civilization.

We’ve had it so good for so long that it’s hard to imagine why we can’t continue.

Ironically, burning fossil fuels and eradicating natural ecosystems that helped keep the carbon cycle in balance, has dangerously destabilised the climate. No matter how much we might wish otherwise, there is no negotiating with the laws of physics and chemistry: we humans are entirely responsible for turning the heat nob on Earth’s thermostat to ‘high’.

Denying the science is like jumping off a cliff while declaring gravity to be a conspiracy theory.

Image: Joseph Chan

Would the climate be getting warmer without humans?

 Summary

  • In the 4.54 billion years since Earth formed, natural climate factors or forcings  have changed Earth’s climate many times.
  • Today, when all natural forcings are added together, Earth should be cooling. Instead, we’re warming rapidly (Figs. 1 & 2).
  • We know from fundamental laws of physics that greenhouse gasses trap heat in the atmosphere. We know we’re emitting lots of them (Video 2) and that’s changing the chemistry of the atmosphere and making it warmer.
  • Any alternative opinion would need to explain not only why global temperatures are rising instead of falling (Figs. 1 & 2), and also why the laws of physics and chemistry have stopped working.
  • The good news is that we can use nature to capture and store excess greenhouse gasses in back the ground, so we can limit the impacts.

Maybe the weather is erratic, but that’s happened before, right? In fact, the nice weather we’ve had for the last 4,500 years allowed us to build a global civilization.

We’ve had it so good for so long that it’s hard to imagine why we can’t continue.

Ironically, burning fossil fuels and eradicating natural ecosystems that helped keep the carbon cycle in balance, has dangerously destabilised the climate. No matter how much we might wish otherwise, there is no negotiating with the laws of physics and chemistry: we humans are entirely responsible for turning the heat nob on Earth’s thermostat to ‘high’.

Denying the science is like jumping off a cliff while declaring gravity to be a conspiracy theory.

Fig. 1: This composite graph from Carbon Brief shows that an increase in temperature from greenhouses gases (red line) matches the warming we’ve observed (light grey line). Each of the natural and anthropogenic cooling and warming ‘forcings’ are explained in WHAT CAUSES CLIMATE CHANGE (menu at the top left).
Fig. 2: The blue line shows that with all the natural climate forcings combined, the planet should be slightly cooling. The red line shows that human factors far outweigh this cooling, even when volcanic eruptions lead to short drops in temperature. NOTE: not all areas of the planet are warming equally. The Arctic and Antarctic are warming much faster that the tropics. On average, the land surface of the Earth is about 5C warmer, and the ocean (which covers 70% of the surface of Earth) are about 0.5C warmer (IPCC, 2021). (Image: Carbon Brief)

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