The basic facts about climate change

A cartoon of the ‘Keeling Curve’  https://keelingcurve.ucsd.edu

The numbers in [square] brackets are from the References.

  • Knowledge of climate change has developed over 200 years; that is no rush to judgment. Now, the international consensus is that human-caused global warming is “unequivocal” and very serious (IPCC 6th Assessment Report 2021/22) [6].

  • The concentration of carbon dioxide in the atmosphere has been rising very fast due to human activities and is now higher than at any time in the last two million years [6]. The level of warming is directly linked to this concentration [6].

  • Warming will stop rising only once we stop emissions [6], so stopping burning coal, oil and gas is imperative. Currently, there is no sign of global emissions reduction [14].

  • Extreme weather events are becoming more frequent and more intense, just as scientists told us they would [17].

  • Wind and solar for electricity generation are now extremely competitive [13], and we can electrify much of our energy use using electric vehicles for transport and heat pumps for heating (see The Future is Electric)

  • The top 10% of people in the world are responsible for 50% of emissions, and the lowest 50% are responsible for just 10% of emissions [2]. But the poorest are in countries that are already feeling the impacts of global warming. This is not fair.

  • Carbon Dioxide is the dominant greenhouse gas driving climate change at present [6], but Methane and Nitrous Oxide from agriculture are also significant. Water vapour is a greenhouse gas that doesn’t drive climate change, but amplifies carbon dioxide’s warming effect [16].

“Climate change has already influenced the likelihood of temperature extremes in the UK. The chances of seeing 40°C days in the UK could be as much as 10 times more likely in the current climate than under a natural climate unaffected by human influence.”

(This was a statement from the UK MetOffice on 30th June 2020 [17], about 2 years before the UK actually experienced over 40°C days. We should follow and trust the science).

For a very accessible set of short videos on various questions you may have, go to Dr Katharine Hayhoe’s

‘Global Weirding’ Youtube channel [8]

Want to understand the Greenhouse Effect but are too nervous to ask? See this short but accurate and accessible video, suitable for a lay person: https://www.howglobalwarmingworks.org

Fancy seeing a fun and very short (1’40”) video explaining the basics of a heat pump? Here’s just what you need:

Basics of a heat pump