Climate Change on a Little Planet

The Little Planet

Asteroid 325.

Science and Sin

Should I wait for the next iPhone?


  • I’ll always be giving numbers for average people in the US and UK. If you eat a cow a day, you’ll have a lot more impact on emissions when you go vegetarian. I’ll give you enough details to adjust everything for your own circumstances.
  • The longer you have left on Earth, the more you’ll affect 2100 temperatures. It’s 2020 now; I’m going to assume you’ll be around until 2070. I had to pick something, and 50 years is a round number. You can approximately adjust for your own life expectancy if you like; halve the numbers for 25 years, and so on.
This is not a recommended method for controlling global warming.


  • Actions that cool the Little Planet by 1.0 °C are a huge deal; that gets us from 3 °C in 2100 to 2 °C in 2100, which makes a huge difference in practice.
  • Actions that cool the Little Planet by 0.1 °C are well worth doing; they reduce flooding, etc., by a noticeable amount.
  • Actions that cool the Little Planet by 0.01 °C or less have a tiny effect on climate change. Focusing on them may make things worse by diverting effort from substantive actions.
Reuse beats recycling.


  • A lot of recycling is mixed, and separating paper, plastics, etc., takes even more energy.
  • Even after separation, not everything is recycled; due to contamination and other factors, a lot goes to landfill or incineration.
Left from a good Guardian article. Right generated from this data.
Flying solo on a private plane is terrible for global warming.


I know it’s vegan, but leave it alone.


From here.
  • Going vegetarian cools the Little Planet by about 0.12 °C in 2100.
  • Going vegan instead cools it by about 0.15 °C in 2100.
Please do not Galileo me.


Unless you will ever contemplate lighting a forest fire, the decision to reproduce is probably the biggest carbon choice you will ever make.

  • ‘Tolerable’ lifestyle changes can only give a 30% reduction in energy use and emissions.
  • People can be pretty effective at teaching children to recycle, which has about as much effect on warming as singing Kumbaya. But there’s almost no correlation between parents’ energy use and their children’s, even before they leave home. So you’re unlikely to get near to that 30% reduction.

Home Energy Use


For the 2100 temperature of your own Little Planet, start at 3.1 °C (US) or 2.3 °C (UK) and add these numbers.

Recycling has a negligible effect on the Little Planet. Driving, flying and diet have significant effects. How many children you choose to have has a much larger effect than anything else.

Thank you for reading.



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Key science, with sources. Minus bad statistics. Minus shaky methodology. Minus politicisation, left or right.