How the Earth responds to climate change

Article by Isabel Key and Mina Frost.

Everything on Earth, underground, and in the atmosphere interacts in complex ways: this is sometimes called the Earth system [1]. When greenhouse gases make the atmosphere warmer, this has a range of effects on the Earth system [2]. In the last few posts we have delved into how this can cause “positive feedback loops”, whereby a response by the Earth system to a change in temperature leads to even more temperature rise [3,4].

But the opposite can also happen! In some cases, an increase in temperature causes a response in the Earth system that triggers a decrease in temperature, stabilising the climate [3,8,9]. Unsurprisingly, this is an example of a “negative feedback loop” [3,4]! You can think of them like human sweat: when you get too hot, sweating cools your skin because evaporation of water take energy from your body, making you less likely to overheat [5].

One of the most important negative feedbacks for climate change is “lapse rate” feedback : there is a temperature gradient linked to height which means the Earth’s atmosphere gets cooler the higher you go [11]. This gradient (or lapse rate [12]) is changing due to climate change [6]. In the tropics, the top of the atmosphere is warming more than the lower part [6]. This allows more infrared radiation to escape into space , cooling the atmosphere – it’s negative feedback [6,7,13].

Near the poles, the opposite is the case: the lower atmosphere is warming faster, leading to less efficient radiation loss into space. This is a positive feedback [6,7,13], but it is thought to be outweighed by the negative feedback occurring in the tropics [9].

Unfortunately, the stabilising effect of negative feedbacks is outweighed by the destabilising effect of positive feedbacks [8,9,10]. Overall, the Earth System amplifies the warming effect of greenhouse gases [8,9], but we can be grateful to negative feedback for slowing the rate of warming [8]!

References

Join our Newsletter!

Impress

Climate Science Ltd
Company Nr: 12370672
Registered in England & Wales
Mail: [email protected]

address

15 Hope Close
Totnes
TQ9 5YD
United Kingdom

Climate Science is registered as a non-profit company limited by guarantee in England and Wales.

Copyright © 2019-2020 Climate Science Ltd. All rights reserved.

Climate Science uses Cookies to ensure you get the best experience on our website.