Once fire-proof Amazon rainforests have become flammable, thanks to climate change

A forest fire in the Amazon. Image: Getty.

The Amazon rainforest is described as the planet’s lungs for good reason. So much carbon is locked up in its trees that protecting the forest is a must if we want to do something about global warming. However, reducing the CO₂ that is emitted when a tropical forest is destroyed depends not only on stopping the actual deforestation, but also on fighting wildfires within the forest.

In a new study published in Nature Communications we show that forest fires are responsible for a huge portion of the carbon emitted from the Brazilian Amazon. During drought years, these fires can emit around a billion tonnes of CO₂. That alone is double the amount of carbon effectively emitted through deforestation in the Amazon.

Humans are throwing vast amounts of CO₂ into the planet’s atmosphere. While in developed countries such as the US and UK most of the emissions come from industrial activities, in developing tropical countries such as Brazil, most come from forests being chopped down and burnt.

Yet while deforestation is already recognised as an important driver of carbon emissions, wildfires under the forest canopy present a less visible but still pernicious threat. To figure out just how bad the problem is, we combined satellite data on the current climate, atmospheric carbon content and the health of forest ecosystems. Our work revealed that emissions from tropical forest fires are growing, even though they are still not normally accounted for in estimates of national emissions.

Wildfires – but not natural fires

Wildfires in the Amazon are not natural events, but are instead caused by a combination of droughts and human activities. Both anthropogenic climate change and regional deforestation are linked to increases in the intensity and frequency of droughts over Amazonia.

Fires spreads into the forest during the 2015 drought. Image: Erika Berenguer/author provided.

This kicks off a nasty cycle: as trees have less water during such droughts, their growth slows and they’re less able to remove CO₂ from the atmosphere through photosynthesis. Trees then shed extra leaves or even die, which means more wood and leaves are ready to burn on the forest floor and, without a dense canopy to retain moisture, the forest loses some of the humidity which acted as natural fire prevention.

These changes are exacerbated by “selective logging” of specific tree species, which opens up the canopy and further dries out the understory and forest edges, which are drier than the interiors. The result: normally fire-proof rainforests become flammable.

A fiery future?

The resulting wildfires have reached a worrying level, burning millions of hectares during the recent El Niño. But the worst could still be to come, as the unusually warm conditions in the Atlantic or Pacific oceans that have caused previous droughts are expected to intensify.

So far this century the Amazon has already experienced three “droughts of the century”, in 2005, 2010, 2015-2016. If the climate science is accurate, and if no action is taken to efficiently predict and avoid fires occurring, we expect that carbon emissions from forest fires would be sustained even if deforestation ended overnight.

Smouldering tree trunk after a forest fire during the 2015 drought in eastern Amazonia. Image: Erika Berenguer/author provided.

As one of the signatories to the Paris agreement on climate change, Brazil is committed to reducing its emissions to 37 per cent below 2005 levels by 2025. A major reduction in deforestation rates over the past decade is a great start. However, deforestation policy doesn’t help reduce forest fires and consequently isn’t fully efficient in mitigating carbon emissions from the Amazon.

Brazil has made substantive advances in reporting emissions from deforestation. It now needs urgently to focus on incorporating CO₂ losses from wildfires into its estimates. After all, those fire emissions are expected to increase in future, thanks to more extreme droughts, an expansion of selective logging, and the ongoing use of fire to manage pasture or to remove regrowing vegetation on farmlands.

Kilometres of burned forests (magenta) spread across old-growth forests (green) in eastern Amazonia. White patches are clouds. Image: Celso Silva-Junior/USGS/author provided.

Given that fire is an essential part of many smallholders’ livelihoods, it is critically important to implement sustainable and socially-just policy responses. Brazil should start by reversing the budget cut to the organisation that oversees its only existing fire-prevention programme. It should also avoid selective logging in regions that are prone to fires, and ensure forest management always factors in long-term fire-prevention.

The ConversationIn summary, these findings are not only critical for policymakers in Brazil to strengthen the efforts of effectively quantifying and limiting carbon emissions from forest fires in the years ahead, but also to other tropical nations to tackle the potential impacts of drought-induced fires on their carbon budget. These new findings bring critical information for nations to help prepare for urgent actions aiming to mitigate the potential increase of fire emissions in response to the intensification of droughts in tropical ecosystems.

Luiz Aragão, Senior Lecturer in Earth Systems Sciences, University of Exeter; Jos Barlow, Professor of Conservation Science, Lancaster University, and Liana Anderson, Research Associate in Land Cover Dynamics and Carbon Emissions, University of Oxford.

This article was originally published on The Conversation. Read the original article.


 

 
 
 
 

“A story of incompetence, arrogance, privilege and power”: A brief history of the Garden Bridge

Ewwww. Image: Heatherwick.

Labour assembly member Tom Copley on a an ignominious history.

The publication last week of the final bill for Boris Johnson’s failed Garden Bridge has once again pushed this fiasco into the headlines.

As well as an eye-watering £43m bill for taxpayers for this Johnsonian indulgence, what has been revealed this week is astonishing profligacy by the arms-length vehicle established to deliver it: the Garden Bridge Trust. The line by line account of their spending reveals £161,000 spent on their website and £400,000 on a gala fundraising event, amongst many other eyebrow raising numbers. 

Bear in mind that back in 2012, Johnson promised that the bridge would be entirely privately funded. The bridge’s most ardent advocate, Joanna Lumley, called it a “tiara for the Thames” and “a gift for London”. Today, the project would seem the very opposite of a “gift”.

The London Assembly has been scrutinising this project since its inception, and I now chair a working group tasked with continuing our investigation. We are indebted to the work of local campaigners around Waterloo as well as Will Hurst of the Architects Journal, who has brought many of the scandals surrounding the project into the open, and who was the subject of an extraordinary public attack by Johnson for doing so.

Yet every revelation about this cursed project has thrown up more questions than it has answers, and it’s worth reminding ourselves just how shady and rotten the story of this project has been.

There was Johnson’s £10,000 taxpayer funded trip to San Francisco to drum up sponsorship for the Thomas Heatherwick garden bridge design, despite the fact that TfL had not at that point even tendered for a designer for the project.

The design contest itself was a sham, with one of the two other architects TfL begged to enter in an attempt to create the illusion of due process later saying they felt “used”. Heatherwick Studios was awarded the contract and made a total of £2.7m from taxpayers from the failed project.


Soon after the bridge’s engineering contract had been awarded to Arup, it was announced that TfL’s then managing director of planning, Richard de Cani, was departing TfL for a new job – at Arup. He continued to make key decisions relating to the project while working his notice period, a flagrant conflict of interest that wouldn’t have been allowed in the civil service. Arup received more than £13m of taxpayer cash from the failed project.

The tendering process attracted such concern that the then Transport Commissioner, Peter Hendy, ordered an internal audit of it. The resulting report was a whitewash, and a far more critical earlier draft was leaked to the London Assembly.

As concerns about the project grew, so did the interventions by the bridge’s powerful advocates to keep it on track. Boris Johnson signed a mayoral direction which watered down the conditions the Garden Bridge Trust had to meet in order to gain access to further public money, exposing taxpayers to further risk. When he was hauled in front of the London Assembly to explain this decision, after blustering for while he finally told me that he couldn’t remember.

David Cameron overruled the advice of senior civil servants in order to extend the project’s government credit line. And George Osborne was at one point even more keen on the Garden Bridge than Johnson himself. The then chancellor was criticised by the National Audit Office for bypassing usual channels in order to commit funding to it. Strangely, none of the project’s travails have made it onto the pages of the London Evening Standard, a paper he now edits. Nor did they under his predecessor Sarah Sands, now editor of the Today Programme, another firm advocate for the Garden Bridge.

By 2016 the project appeared to be in real trouble. Yet the Garden Bridge Trust ploughed ahead in the face of mounting risks. In February 2016, despite having not secured the land on the south bank to actually build the bridge on, nor satisfied all their planning consents, the Trust signed an engineering contract. That decision alone has cost the taxpayer £21m.

Minutes of the Trust’s board meetings that I secured from TfL (after much wailing and gnashing of teeth from the Trust itself) reveal that weeks beforehand Thomas Heatherwick had urged the trustees to sign the contract in order to demonstrate “momentum”.

Meanwhile TfL, which was represented at board meetings by Richard de Cani and so should’ve been well aware of the mounting risks to the project, astonishingly failed to act in interests of taxpayers by shutting the project down.

Indeed, TfL allowed further public money to be released for the project despite the Trust not having satisfied at least two of the six conditions that had been set by TfL in order to protect the public purse. The decision to approve funding was personally approved by Transport Commissioner Mike Brown, who has never provided an adequate explanation for his decision.

The story of the Garden Bridge project is one of incompetence, arrogance and recklessness, but also of privilege and power. This was “the great and the good” trying to rig the system to force upon London a plaything for themselves wrapped up as a gift.

The London Assembly is determined to hold those responsible to account, and we will particularly focus on TfL’s role in this mess. However, this is not just a London issue, but a national scandal. There is a growing case for a Parliamentary inquiry into the project, and I would urge the Public Accounts Committee to launch an investigation. 

The Garden Bridge may seem like small beer compared to Brexit. But there is a common thread: Boris Johnson. It should appal and outrage us that this man is still being talked about as a potential future Prime Minister. His most expensive vanity project, now dead in the water, perhaps serves as an unwelcome prophecy for what may be to come should he ever enter Number 10.

Tom Copley is a Labour member of the London Assembly.