How to reach net-zero?

Article by Isabel Key and Mina Frost.

To reach “net-zero” emissions we need to not only reduce greenhouse gas emissions, but also to remove CO2 from the atmosphere [15] (for more on what “net-zero” means, see yesterday’s post). How can we remove CO2?

1) Direct Air Capture: there are a few teams of engineers building machines which “suck” CO2 out of the air [e.g. 8,9]. However, this is currently very expensive, costing over $100 to remove one tonne of CO2 [10].

2) Bio Energy with Carbon Capture and Storage (BECCS) [11]: this involves growing plants, which naturally take up CO2 from the air as part of photosynthesis, and burning them in a power station to generate electricity [11]. Burning the plants releases the CO2 that they originally took up, but machinery can be used to capture the CO2 again and store it so it doesn’t enter the atmosphere [11].

3) Restoring natural ecosystems [12]: it has become popular for organisations and governments to plant lots of trees [1,2,3] to take CO2 out of the air [16]. We need to avoid plantations of just one tree species (monocultures) which are vulnerable to climatic extremes, pests and disease, and avoid replacing other natural habitats like grassland which can be more resilient to drought and wildfire [13].

4) Using soil to take up CO2, by changing farming practices [17]: this can also make crops grow better and improve food security [17].

We likely need a combination of methods for removing CO2 from the atmosphere [14]. However, to successfully slow climate change we need every country on board [7]. This is a big challenge. For example, Russia was the 4th biggest contributor of global CO2 emissions in 2017 [6] but has weak climate targets; if every country had similar targets to Russia then global warming would exceed 4°C [5], rather than staying below 1.5°C as governments have agreed to aim for [4].

References

[1] https://www.weforum.org/agenda/2018/07/pakistan-s-billion-tree-tsunami-is-astonishing/

[2] https://info.ecosia.org/what

[3] https://www.gov.uk/government/news/government-launches-new-scheme-to-boost-tree-planting

[4] https://unfccc.int/process-and-meetings/the-paris-agreement/the-paris-agreement

[5] https://climateactiontracker.org/countries/russian-federation/pledges-and-targets/

[6] https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions See: Share of global CO2 emissions by country, 2017

[7] https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_summary-for-policymakers.pdf See: SPM.2 paragraph 5 (“Effective mitigation will not…”)

[8] http://carbonengineering.com

[9] https://www.climeworks.com/

[10] https://www.american.edu/sis/centers/carbon-removal/upload/fcea_wps002_ishimoto.pdf See: Cost estimates by technology developers

[11] https://www.sciencedirect.com/science/article/pii/S030626191730291X#b0010 See: Introduction

[12] https://www.nature.com/articles/s41558-019-0405-0 See: A focus on forests

[13] https://www.nature.com/articles/s41558-019-0405-0 See: The problem with monocultures & What about the rest?

[14] https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_summary-for-policymakers.pdf See: SPM.4 paragraph 4

[15] https://www.ipcc.ch/sr15/chapter/chapter-4/ See: 4.3.7 Carbon Dioxide Removal (CDR)

[16] https://www.ipcc.ch/sr15/chapter/chapter-4/ See: 4.3.7.2 Afforestation and reforestation (AR)

[17] https://www.ipcc.ch/sr15/chapter/chapter-4/ See: 4.3.7.3 Soil carbon sequestration and biochar

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.