• About
    • Which Energy Mix is this?
  • Climate News Network Archive
  • Contact
The climate news that makes a difference.
No Result
View All Result
The Energy Mix
  • Canada
  • UK & Europe
  • Fossil Fuels
  • Ending Emissions
  • Community Climate Finance
  • Clean Electricity Grid
  • Cities & Communities
SUBSCRIBE
DONATE
  • Canada
  • UK & Europe
  • Fossil Fuels
  • Ending Emissions
  • Community Climate Finance
  • Clean Electricity Grid
  • Cities & Communities
SUBSCRIBE
DONATE
No Result
View All Result
The Energy Mix
No Result
View All Result
  • Canada
  • UK & Europe
  • Fossil Fuels
  • Ending Emissions
  • Community Climate Finance
  • Clean Electricity Grid
  • Cities & Communities
  FEATURED
BP Predicts Faster Oil and Gas Decline as Clean Energy Spending Hits $1.1T in 2022 January 31, 2023
Canada Needs Oil and Gas Emissions Cap to Hit 2030 Goal: NZAB January 31, 2023
Ecuador’s Amazon Drilling Plan Shows Need for Fossil Non-Proliferation Treaty January 31, 2023
Rainforest Carbon Credits from World’s Biggest Provider are ‘Largely Worthless’, Investigation Finds January 31, 2023
Danske Bank Quits New Fossil Fuel Financing January 23, 2023
Next
Prev

Massive Tree Planting Brings Only Limited Climate Gain, Researchers Warn

June 2, 2021
Reading time: 4 minutes
Full Story: The Conversation @ConversationUS
Primary Author: Simon Lewis @SimonLLewis, Alexander Koch @kochalex_, Chris Brierley @cmbrierley

Bureau of Land Management Oregon/Flickr

Bureau of Land Management Oregon/Flickr

 

What would happen if every single patch of farmland in the tropics, from Brazil through Congo, India and Indonesia, was abandoned overnight and left to turn back into forests? That’s the question three climate scientists investigated in what they describe as a “hypothetical and idealized experiment”—and the answer is sobering.

“Trees and forests have become increasingly important in plans to tackle the climate emergency,” write Simon Lewis, Alexander Koch, and Chris Brierley in a post for The Conversation. “Yet our work shows that once you factor in how the soil, oceans, and other parts of the Earth system would respond, tree planting is not as potent a solution as it may first seem.”

  • The climate news you need. Subscribe now to our engaging new weekly digest.
  • You’ll receive exclusive, never-before-seen-content, distilled and delivered to your inbox every weekend.
  • The Weekender: Succinct, solutions-focused, and designed with the discerning reader in mind.
New!
Subscribe

Of course, abandoning agriculture in the tropics cannot be a solution to climate change, they stress. “This was a hypothetical and idealized experiment, but one that helps us to explore how the global carbon cycle might respond to forest restoration and tree planting on a vast scale. And targeting the tropics shows maximum impact, as trees grow fast there.”

To investigate the question, the researchers used the UK Met Office’s climate change model—a computer simulation of the Earth as a system in which the oceans, land, and climate interact and affect each other. They simulated two futures. First, a scenario where the world takes serious action to limit warming to less than 2℃. The second scenario was identical, except all farming across the tropics was stopped and the original vegetation, mostly forests, would recover.

The difference between the two scenarios shows that the new tropical trees would store an extra 124 billion tonnes of carbon by the year 2100. All this extra carbon would have been taken from the atmosphere through photosynthesis. However, carbon in the atmosphere—which matters for climate change—would drop by only 18 billion tonnes. What explains the huge difference?

The reason is that other parts of the Earth system counteract the effect of the new tree growth. If the tropics were reforested, the model predicts that the oceans, soil, and vegetation would absorb less carbon dioxide. By the end of the century, tropical trees would take up an extra 124 billion tonnes of carbon (or 124 gigatonnes, Gt), but tropical soils would take up 83 Gt less carbon, as the turnover of dead plants is much slower in forests compared with grasses and crops that die annually, meaning lower carbon inputs in forest soils and lower carbon storage.

Lower carbon dioxide levels in the atmosphere would also affect vegetation and soils elsewhere in the world. Less carbon dioxide in the atmosphere would mean plant growth slows. And just as in the tropics, less carbon would be taken up by soils.

There would be one other major change to the Earth system. The oceans slow climate change by removing carbon dioxide from the atmosphere: as CO2 levels increase, some of the extra carbon dioxide dissolves into the seawater. And in the model, the oceans would take up less carbon since the new tropical trees would lower atmospheric CO2.

To recap: we started with new trees in the tropics taking 124 Gt of carbon out of the atmosphere. Avoiding deforestation adds a further 10 Gt. But once you subtract the carbon no longer stored in tropical forest soils (83 Gt), in soils and vegetation elsewhere (18 Gt), and in the oceans (15 Gt), you aren’t left with much.

Remarkably, reforesting the tropics—after accounting for soil, vegetation, and ocean responses—results in only 18 Gt of carbon taken from the atmosphere. This is an 86% reduction from the initial extra carbon in tropical trees. This 18 Gt equates to just a 10 parts per million reduction in atmospheric carbon dioxide.

The Earth System Works Against Us

The hypothetical scenario is the reverse of what is happening today, Lewis, Koch and Brierley write. When carbon dioxide is released from burning fossil fuels, a little less than half of those emissions remain in the atmosphere and contribute to climate change. The rest are absorbed by the oceans, soil, and vegetation. This has been a great free subsidy from nature.

But here is the catch: just as the amount of carbon absorbed in the land and ocean increases as we pump more carbon dioxide into the atmosphere, the reverse happens when we take it out of the atmosphere. The Earth system starts to work against us when we plant trees or use other methods of removing atmospheric CO2.

These results are sobering. Even something as radical as reforesting the entire tropics—far beyond any plausible real-world policy outcome—would have less influence on the climate than you might think. But these results also highlight that the best way to avoid dangerous global heating is by not releasing fossil carbon into the atmosphere in the first place.

This article is republished from The Conversation under a Creative Commons licence. Read the original article.

The Conversation



in Carbon Levels & Measurement, Climate & Society, Climate Impacts & Adaptation, Ending Emissions, Forests & Deforestation, Soil & Natural Sequestration

The latest climate news and analysis, direct to your inbox

Subscribe

Related Posts

Mike Mozart/Flickr
Ending Emissions

BP Predicts Faster Oil and Gas Decline as Clean Energy Spending Hits $1.1T in 2022

February 4, 2023
331
Gina Dittmer/PublicDomainPictures
Canada

Canada Needs Oil and Gas Emissions Cap to Hit 2030 Goal: NZAB

January 31, 2023
196
CONFENIAE
Ending Emissions

Ecuador’s Amazon Drilling Plan Shows Need for Fossil Non-Proliferation Treaty

January 31, 2023
61

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

I agree to the Terms & Conditions and Privacy Policy.

Trending Stories

Mike Mozart/Flickr

BP Predicts Faster Oil and Gas Decline as Clean Energy Spending Hits $1.1T in 2022

February 4, 2023
331
openthegovernment.org

BREAKING: U.S. Senate Passes Historic $369B Climate Package

August 8, 2022
541
Sam Balto/YouTube

Elementary School’s Bike Bus Brings ‘Sheer Joy’ to Portland Neighbourhood

October 16, 2022
261
Lucio Santos/flickr

Canadian Banks Increased Fossil Investment in 2021, Report Card Shows

November 27, 2022
116
RL0919/wikimedia commons

Danske Bank Quits New Fossil Fuel Financing

January 23, 2023
2.4k

Recent Posts

Gina Dittmer/PublicDomainPictures

Canada Needs Oil and Gas Emissions Cap to Hit 2030 Goal: NZAB

January 31, 2023
196
CONFENIAE

Ecuador’s Amazon Drilling Plan Shows Need for Fossil Non-Proliferation Treaty

January 31, 2023
61
Ken Teegardin www.SeniorLiving.Org/flickr

Virtual Power Plants Hit an ‘Inflection Point’

January 31, 2023
125
/snappy goat

Rainforest Carbon Credits from World’s Biggest Provider are ‘Largely Worthless’, Investigation Finds

January 31, 2023
94
Victorgrigas/wikimedia commons

World Bank Climate Reforms Too ‘Timid and Slow,’ Critics Warn

January 31, 2023
42
Doc Searls/Twitter

Guilbeault Could Intervene on Ontario Greenbelt Development

January 31, 2023
132
Next Post
mental health

Action is the Antidote as Climate Anxiety Creates Mental Health Crisis

The Energy Mix - The climate news you need

Copyright 2023 © Energy Mix Productions Inc. All rights reserved.

  • About
  • Contact
  • Privacy Policy and Copyright
  • Cookie Policy

Proudly partnering with…

scf_withtagline
No Result
View All Result
  • Canada
  • UK & Europe
  • Fossil Fuels
  • Ending Emissions
  • Community Climate Finance
  • Clean Electricity Grid
  • Cities & Communities

Copyright 2022 © Smarter Shift Inc. and Energy Mix Productions Inc. All rights reserved.

Manage Cookie Consent
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behaviour or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
Manage options Manage services Manage vendors Read more about these purposes
View preferences
{title} {title} {title}