04/12/2017

How Climate Change Can Spread Respiratory Infection

Medical Journal of Australia - Hugo Wilcken


SCIENTISTS and policymakers worry about the economic havoc that climate change will wreak, thanks to rising sea levels, extreme weather events or desertification. But there’s been less emphasis on the effect it is already having on the spread of infectious diseases across human populations.
This is a subject dear to the heart of leading US respiratory specialist Dean Schraufnagel, a Professor of Medicine at the University of Illinois, Chicago. Professor Schraufnagel was in Australia in November 2017 to give a fascinating talk on respiratory infection and climate change at the plenary session of the Asian Pacific Society of Respirology (APSR) Congress, held in Sydney.
“It’s not a question of whether climate change will affect human health. It already has, by altering the epidemiology of climate-sensitive pathogens,” Professor Schraufnagel told MJA InSight.
“When we change the climate, we also change habitats and bring wildlife, crops, livestock and humans into contact with pathogens to which they may have had less exposure and less immunity,” he says.
As a case in point, Professor Schraufnagel points to an outbreak of respiratory disease caused by hantavirus in Panama. Hantavirus is found in the saliva, urine and faeces of rats, the population of which had increased exponentially due to an episode of warm, rainy weather.
“Climate variation had boosted the rat population, which put them in closer proximity to humans, who then picked up the virus from the rats,” Professor Schraufnagel explains.
“The way that climate change acts on the spread of infectious diseases is very complicated, and can involve the migration of wild animals, livestock or humans, and each time there’s a change in habitat, you come into contact with new vectors and situations that can lead to infection. So, as the environment changes, we’re more likely to come into contact with infectious agents.”
In an example closer to home, an Australian study looked at how fluctuating temperatures — another measure of global climate change — can affect pneumonia incidence. It found a correlation between sharp temperature drops from one day to the next and increased emergency visits for childhood pneumonia.
Fungal infection is another area where climate change can play a significant role in the incidence of respiratory diseases.
“Endemic fungi are found in the soil. There was a well documented case, in California, where there was an outbreak of coccidioidomycosis, which is transmitted by inhaling spores and can’t be transmitted from person to person. The cases developed 2 weeks after a severe dust storm, which released the spores from the soil.”
Professor Schraufnagel says risks will vary from region to region, and some regions will be at greater risk than others.
“Borderline areas will be more affected. So arid areas at risk of desertification, or low-lying areas at risk of flooding might be the ones at most risk of respiratory infection.”
He says one of the challenges of dealing with the effect of climate change on infectious diseases is its very complexity.
“If you have a cyclone or an earthquake, you know what the damage is right away. But with climate change, it’s not so straightforward, which allows for deniers and industry lobbyists. I’m from the US, so I’m particularly hard hit by the election of Donald Trump in this regard. But I’m heartened to see the rest of the world and much of the US are still trying to do something about climate. I think we need to educate the public. Doctors and scientists and the media need to get the message out.”
At the APSR Congress, Professor Schraufnagel also chaired a workshop on another controversial topic: electronic cigarettes and respiratory health. He is of the view that e-cigarettes need a tighter regulation than they’re getting now.
“Nicotine is one of the most addictive substances in use. So, I think you have to be very conservative and I’m quite opposed to these nicotine delivery devices. The exception might be if they could be used to help people stop smoking, but that should be done through regulatory agencies. It should be prescribed medicine, or if not prescribed, at least shown to be safe in clinical trials. If the makers want to claim e-cigarettes are useful for smoking cessation, fine. Just do the trials and see what happens.”
He says there has been an increasing amount of research into the harm e-cigarette vapours can do to the lungs.
“All the potential harms of combustible cigarettes are pretty much present, although in a much smaller degree, in e-cigarettes. People say the flavouring they use is safe because they’re already used in foods, but what’s safe for eating is not necessarily safe for breathing.”
He points to diacetyl, a buttery-flavoured chemical in foods like popcorn, which is safe to eat, but when inhaled by workers in food factories was found to cause a fatal bronchitis.
“There are dozens or even hundreds of flavourings used in e-cigarettes and we just don’t know how safe they are. The harm reduction argument for e-cigarettes is fundamentally faulty, because smoking is one of the most dangerous, toxic things you can do to your lungs. To say it’s better to use e-cigarettes is like saying that getting shot with a 22-calibre gun is better than getting shot with a 35-calibre gun. When actually it’s best not to get shot at all!”

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If Oceans Stopped Absorbing Heat From Climate Change, Life On Land Would Average 122°F

Quartz - 

More than 90% of climate change is happening underwater. (AP/NOAA)
Since the 1970s, more than 93% of excess heat captured by greenhouse gases has been absorbed by the oceans. To understand how much heat that is, think of it this way: If the oceans weren’t absorbing it, average global temperatures on land would be far higher—around 122°F, according to researchers on the documentary Chasing Coral. The global average surface temperature right now is 59°F.
A 122°F world, needless to say, would be unlivable. More than 93% of climate change is out of sight and out of mind for most of us land-dwelling humans, but as the oceans continue to onboard all that heat, they’re becoming unlivable themselves.


Ocean temperatures are the highest since record-keeping began, and hundreds of marine species are suffering because of it. Recent back-to-back coral bleaching events—triggered by too-hot sea temperatures—have killed off significant portions (paywall) of the Great Barrier Reef, and a recent UN report warned that the world’s most significant coral reefs could die out completely by the end of the century, if not sooner.
“Warming is projected to exceed the ability of reefs to survive within one to three decades for the majority of the World Heritage sites containing corals reefs,” the report said.
Scientists worry that the warming ocean also risks releasing billions of tons of frozen methane from the thawing seabed. Unlocking that methane, a powerful greenhouse gas, could trigger significant warming here on land.

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One In Six New Cars In The World Will Be Electric By 2025

Bloomberg - Oliver Sachgau

  • UBS predicts 16% of cars sold worldwide in 2025 will be EVs
  • Analysts say consumer interest is rising, especially in China


Why Electric Cars Aren't Taking Over Yet

 Almost every sixth car sold in the world will be electric by 2025, according to a UBS global autos survey released Tuesday. And if things go the way they have in 2017, those cars are more likely to be emblazoned with a Tesla Inc. logo than BMW AG’s.
By the middle of the next decade, global sales of electric vehicles should hit 16.5 million, analysts led by Patrick Hummel said in the report, a 16 percent increase from the previous estimate. They predict electric vehicles will make up 16 percent of all car sales by then, up from a previous estimate of 14 percent.
“The shift to electric cars will come faster and in a more pronounced way, fueled by the diesel demise in Europe, battery technology advancements and regulation in China and Europe,” Hummel said. Europe will have the highest EV penetration, approaching 30 percent of new cars sold.

Established car manufacturers like BMW and Daimler AG are spending billions in a race to gain market share in the burgeoning electric-car market, hoping their existing scale will help them leapfrog newer companies like Tesla that focus exclusively on electric vehicles.
One of the reasons behind the upgraded forecast is a new dual-credit policy in China that makes electric-vehicle sales and production compulsory, according to the note. Respondents in China were most likely to say they were considering buying an electric car, at 58 percent, while those in Germany were the least likely, at 14 percent. Higher-than-expected EV sales in 2017 also boosted the forecast, the analysts said.
Hummel expects Tesla to benefit the most from the rise in electric vehicles, as the Palo Alto, California-based company had the highest jump in EV-brand credibility in the survey. Munich-based BMW could suffer the most from a Tesla rise, as the company’s 3-series is seen as the closest competitor to Tesla’s Model 3.
“Tesla’s increasing popularity seems directly correlated by the launch of the Model 3, the brand’s first mass-market car. Most of the other brands have lost ground in the current survey,” Hummel said.
Still, Tesla’s rise is not guaranteed, the note said, as premium brands that have yet to release their own electric car, like Volkswagen AG’s Audi and Porsche, are still preferred to Tesla.

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03/12/2017

Environment: A Legal Milestone

Irish Times - Editorial

High Court’s recognition of constitutional right to environmental protection is to be commended
Irish High Court
The recognition for the first time in an Irish court of a constitutional right to environmental protection “that is consistent with the human dignity and well-being of citizens at large” is a legal milestone. It is to be commended as a provision for the public good.
The High Court decision last week arose in a case brought by the environmental group Friends of the Irish Environment (FIE), and emerged in spite of their challenge to planning permission for a new runway at Dublin Airport being dismissed.
The right will add to the legal armoury for those living with the consequences of persistent environmental damage; citizens experiencing long-term pollution that is often a threat to their health; and people living with negative impacts of climate change where legally-binding measures and targets for reducing carbon emissions are not being adhered to.
A right to an environment that is consistent with the human dignity and wellbeing of citizens at large is an essential condition for the fulfilment of all human rights
FIE had argued the proposed runway would result in additional greenhouse gas emissions which would increase the pace of climate change.
In his judgment, Mr Justice Max Barrett said: “A right to an environment that is consistent with the human dignity and wellbeing of citizens at large is an essential condition for the fulfilment of all human rights”.
It is an indispensable existential right that is enjoyed universally, yet which is vested personally as a right under Article 40.3.1 of the Constitution, he found. “It is not so utopian a right that it can never be enforced.”
The State had argued there was no unenumerated, or unwritten, right to an environment in the Constitution.
The Environmental Pillar – an alliance of environmental groups – had called for a referendum to give a constitutional right to environmental protection to the people of Ireland in its submission to the Citizens’ Assembly on climate change.
But this was not taken up in that body’s recommendations to the Government.
Instead, the right has become available via a different channel.
It is a progressive move that will greatly assist those seeking to hold the Government and State accountable for their responsibilities on the environment and climate change.

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Drones Spray Tree Seeds From The Sky To Fight Deforestation

National Geographic - Erin Stone

 These innovators are combating climate change and restoring forests with the latest technology.
This video from BCE demonstrates how the reforestation project works. 

Every year, about 15 billion trees are cut down to make way for agriculture, mining, logging, and urban sprawl. Such mass deforestation has accelerated global warming and imperiled the survival of millions of species. Though many nations, organizations, and even individuals have tried, no one has been able to plant enough trees to make up for that loss—but some innovative entrepreneurs are working on a high-tech solution.
BioCarbon Engineering (BCE), a U.K.-based start-up, has developed a technique that they say could potentially plant one billion trees per day. The method? Drones.
Current tree-planting programs "are just not fast enough,” said Irina Fedorenko, a co-founder of the company. “But our technology is automated, so we can scale up quite realistically and quite quickly.” (Learn about the teenager who is on track to plant a trillion trees.)
Trees are critical to absorbing the greenhouse gases that contribute to global warming. Without them, the speed and severity of climate change will continue to escalate. But for their part, BCE has dubbed their strategy “industrial-scale reforestation.”
First, a drone scans the terrain and develops a 3-D map of the area. Then, using the data from this “smart map,” the team develops an algorithm for a unique planting pattern. A “firing drone” uses the algorithm to carry out the planting strategy. The drone flies about six feet above the ground, firing germinated seed pods at a speed that will get them under the soil. One drone operator can manage six drones.
It’s similar to strategies used for precision farming, except in this case, the firing drones take the place of tractors—“sky tractors,” as Fedorenko refers to them.
The system’s designers say their technique is much more efficient and accurate than regular aerial seeding methods. Initial testing in the U.K. found that the species planted by drone had a better survival rate than helicopter spreading that's more commonly used. Some species even had survival rates nearly identical to hand planting.
“We are bridging this gap between ground-based technologies like tractors and aerial technologies such as helicopters,” Fedorenko says.
Speed is the most revolutionary aspect of BCE’s “precision planting” technology, but the drones can also reach places that tractors and humans cannot, at least without significant bodily risk—for example, steep mountainsides or areas with contaminated soil. Drones may even one day help terraform other planets.
But it’s not just about trees: “We have a title of tree-planting drone company, but we also do grasses, bushes, flowers, and a lot of fungi,” Fedorenko says. “It’s about restoring what is right for the environment, not just trees.”


India Man Plants Forest Bigger Than Central Park to Save His Island
This film is part of National Geographic's Shortfilm Showcase, and any views expressed here belong to the filmmakers. 

Pioneer plant species are usually the most successful, “but the general rule is that if you can restore the forest from seeds, then you can use drones to do that,” Fedorenko says.
In June, BioCarbon planted 5,000 trees in a day to rehabilitate land ravaged by coal mining in Dungog, Australia. They’ve also worked in South Africa and New Zealand. Since the company’s inception, they’ve used drones to plant more than 25,000 trees across the globe.
“If you re-forest a large area of land, you bring back not just fertile soil, but you can really impact local climate, improve the water table, carbon sequestration, increase biodiversity, and, of course, landscapes are never empty so you always have people who are benefiting from the ecosystem,” Fedorenko says.

The Big Picture
Experts caution that planting itself is not always as important as protection from factors such as overgrazing, agriculture, and fires, to allow natural regeneration of forests to occur. Some experts worry that the efficiency of drone reforestation could even lower motivation for countries to save existing forests. Additionally, in traditional reforestation enterprises, the planting work can provide employment for communities that need it—jobs that could one day be replaced by drones.
"It's probably easier, in the short term, to plant trees with a drone than fix the issues on the ground, but in the long run, that fix is necessary," says Richard Houghton, a senior scientist at the Woods Hole Research Center, a climate change think tank based in Massachusetts. "A technical fix is generally easier than social change, but not as long lasting."
With constantly improving GPS and imaging technologies, experts agree that drones have become very useful for accurately mapping large swaths of land and measuring tree and vegetation growth or degradation—even mapping carbon sequestration. But some scientists are more skeptical about their success as a planting technology to combat deforestation on a large scale. For one thing, they only have so much range and battery life.
"Drones are good for measuring secondary growth and looking at where the forest is coming back, but you fight deforestation at a socioeconomic level," says Arturo Sanchez, director of the University of Alberta's Center for Earth Observation and Sciences. "The issue of climate change is not forest restoration, the issue is energy. It is controlling coal plants, power plants, automobile emissions. Planting trees is very important, but when you look at the distribution of CO2 emissions, deforestation accounts for 10 to 15 percent. The rest is energy. That’s what needs to be controlled."
Fedorenko acknowledges that drones alone cannot eliminate all the causes or impacts of deforestation, but she says they could become a useful tool. (See how drones set controlled burns by shooting fireballs.)

 Field Tests
BCE just started work on a large-scale project to plant mangroves in Myanmar, incorporating this integrated approach to ecosystem restoration. Mangroves in Myanmar’s low-lying Ayeyarwady Delta have been decimated by years of deforestation for agriculture and aquaculture—eighty-four percent of the original mangrove cover is gone.
“Mangroves have huge potential to actually save people’s lives because they protect coastal communities from tsunamis,” Fedorenko says. “Not only do they have an impact on the ecosystem, like fish stocks, so that people can maintain their livelihoods, but they are also a literal shield from the ocean.”
Their tangled roots also protect coastal areas from erosion.
The project spans more than 600 acres and involves a “holistic” approach to measuring success: BCE will be partnering with local women farmers, training and employing them to collect and prepare the seeds, as well as monitor the ecosystem as the project progresses. BCE will be able to assess whether the mangroves are growing successfully in less than a year.
Mangrove forests are also some of the most carbon-rich habitats on the planet, sequestering carbon up to 100 times faster than terrestrial forests. That means they’re incredibly efficient at mitigating the impact of global warming.
The project is one step closer to BCE’s main goal: “Of course, our ultimate ambition is to stop climate change,” Fedorenko says with a smile.

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ASX Top 20 Companies For Climate Change Reporting In 2017

RenewEconomy - 

Climate change reporting requirements are increasing
In a note published  November 3 we looked at the Financial Stability Board’s recommendations on climate related financial disclosures.
We noted that the Financial Stability Board has many of the world’s Reserve Banks as members, as well as the IMF, and could be regarded as providing significant credibility to climate reporting by the corporate sector – and perhaps as providing momentum on the need for an Accounting Standard that would cover climate risk.

What companies actually disclosed this year
Is QBE the worst?
In this note we briefly looked at the top 20 companies by market capitalization listed on the ASX to see what they actually said in their latest annual report. Mostly this is 2017 but in some cases its still 2016.
We rated each company out of 5 on disclosure.  This was a qualitative score awarded by my co researcher on this program, Bella Leitch, a student at Macquarie University.
However, I reduced QBE’s score. For an insurance company that also does reinsurance not to mention climate change seems poor.
Your analyst works to the view that companies that do a thorough job on sustainability (which has many dimensions, not just climate change) will tend to be survive for longer. An unenlightened view will eventually lead to investors penalizing the rating.
At this stage we are just interested to monitor what companies are actually saying this year.

Research method
At each company’s website we  searched the following documents: annual review for 2016/17, sustainability reports (for the companies that had them) and also general announcements.
We then searched the documents for these following words: climate, carbon, warming, environment and sustainability. The text was then summarized.

S&P/ASX 20 Index (1 November 2017)
Company Mkt  cap A$bn ITK summary of company statements What they actually say Score (1-5)
Commonwealth Bank of Australia 136 Mention as a 2017 highlight the 2.8bn lent to renewable energy projects. Mention “environmental stewardship” – say they are in line with the Paris agreement as well as enacting additional sustainable and ethical investment options. They have a Sustainable Property Strategy to monitor their direct carbon emissions and energy use. They understand that climate change is a large risk both financially and non-financially for the bank. By taking additional contribution above their core businesses they hope to have positive influences on their customer relationships  as their customers change their preferences and behaviours. 5
Westpac Banking Corporation 113 Limited discussion. Released refreshed climate change policy this year.  Mention climate change only within their sustainability leadership section. Issued a climate change position statement nd 2020 action plan. Say they have competitive advantage in their sustainability culture. Within their strategic priorities for sustainability, environmental solutions are briefly discussed including a short statement of their committed exposure to environmental and clean tech industry and a revised climate change policy. 2
Australia and New Zealand Banking Group Limited 88 One of their key highlights of 2017 is reducing greenhouse gas emissions by 20% on premises from 2013. They mention $6.9bn funded and facilitated in low carbon and sustainable solutions since 2015. Mention how their stakeholders value responsible business loans in areas such as climate change and encouraging its limited impact. Discuss how the environment and climate change is a major trend that is shaping society. Their  reporting reflects the Financial Stability Board's (FSB) Task Force on Climate-Related Disclosures (TCFD) recommendations, which is also discussed by the CEO. They understand that climate change is a large risk both financially and non-financially for the bank. They have begun to take many steps to accommodate and finance the movement to a low carbon economy. 5
National Australia Bank Limited 88 Climate change is first mentioned in the environmental, social and government (ESG) risk management section. They have an environmental financing commitment of $55bn by 2025 in order to help address climate change and transition to a low carbon economy. They recognise that climate change is a significant risk. They recognise the risk that is climate change and have implemented various strategies to address this issue. In order to understand the implications of the Paris agreement and refresh climate change policy,they have created a Climate Change Working Group .. However it is not mentioned as a key highlight for NAB 3
BHP Billiton Limited 87 Discuss climate change management as a key goal – it is treated as a board level governance issue. Their greenhouse gas emissions were reduced by 21% from 2006. Climate change is core to their strategic decision making. Large discussion on the risks of climate change in their fossil fuel products and the growth of renewable energy. Also discuss the physical impacts of climate change e.g. such as changes in rainfall patterns on the collection of their products.  Include an entire section of the annual report on climate change and their response to it. Climate change is going to have a major impact on their industry both physically and non-physically. As such they are trying to reduce their own carbon footprint and improve their image in order to compete with the rise in renewable energy and limit the impact of negative press on fossil fuels. 5
CSL Limited 63 Very limited discussion. They say they meet Australian regulations in regard to the Government's greenhouse reporting act. Environmental and climate change risks are monitored to ensure compliance with regulatory requirements. As environmental impact is of special importance to select investors so CSL commits to initiative such as CDP CSL has met its reporting obligations under the Australian Government's National Greenhouse and Energy Reporting Act (2007) 1
Wesfarmers Limited 48 Limited discussion. When discussing their sustainability operating, they briefly mention an aim to reduce their impact on climate change. It is noted as a risk for the future. They have a climate change resilience aim – which has enacted a climate change strategy including two degree scenario analysis and carbon shadow pricing. There is an evaluation of the risk of climate change, however it is not one of their key goals. They aim to keep up with national standards and are planning accordingly for the changes predicted with climate change. 2.5
Telstra Corporation Limited 42 Mention it as a goal as apart of their sustainable future. 68% reduction greenhouse gases from baseline year. They recognise climate change as a global challenge and it is one of their goals to combat this. They will use technology to address their environmental challenges e.g. Telstra’s cloud calculator tool . There is recognition of the impact climate change will have and a demonstrated aim to reduce their and their customers level of greenhouse gas emissions. However there are many other goals and aims that appear to take a more centre stage at the moment for Telstra. 2
Woolworths Limited 34 Very limited discussion. Mention an increase in use of solar energy. Climate change is mentioned as a part of a strategic risk and they discuss very briefly how they have CRS to improve sustainability. They recognise climate change as a generic risk that could  adversely affect the group’s performance. 1
Macquarie Group Limited 33 There is limited discussion regarding climate change. They talk of continued  commitment to low-carbon growth sectors under the ESG highlights. They also include climate change in their risk analysis. They continue to plan and strategise regarding the impacts of climate change however, there is very limited discussion and it is not one of their key priorities. 1.5
RIO Tinto Limited 30 *This comes from 2016 annual report – 2017 annual report not released yet. Published their first climate change report in 2016.  7% reduction in GHG from 2015 to 2016 – this is indicative of their ability to respond to future legislative costs and climate policies. Recognise both physical and non-physical risks of climate change.  Mention ability to respond to climate change as a goal of 2017. In 2016, Shareholders passed a resolution to report on climate change. Limited discussion. They understand that climate change will be a risk to them in the future and are beginning to report and account for this risk, but as of the present there are larger issues for them. 1.5
Woodside Petroleum Limited 26 *This comes from 2016 annual report – 2017 annual report not released yet. Climate change was recognised at the top material rick to Woodside. Developed a climate change and carbon strategy in 2016. Recognition of it as a risk and are developing strategies to deal with it in the future, however are only just beginning to deal with it. 1
Transurban Group Stapled 25 There is no mention of climate change. Closest mention is that one of the directors is also on the board of the climate change council and that they are trying to reduce environmental footprint with the develop of new roads/tunnels N/A 0
Scentre Group Stapled 21 *This comes from 2016 annual report – 2017 annual report not released yet. No mention of climate change or global warming. Brief discussion of decrease in GHG in separate sustainability report N/A 0.5
Suncorp Group Limited 18 11% reduction in greenhouse gas emissions. Climate change is discussed as a key external risk. Comply with the National Greenhouse and Energy Reporting Act 2007 Recognition of it as a risk and are developing strategies to deal with it in the future, however it is not a key focus area. 1.5
Westfield Corporation Stapled 16 Very brief mention of climate change as a potential risk. Further brief discussion in separate sustainability report Recognise it as a future risk. 1
Insurance Australia Group Limited 16 The Group’s sustainability performance is managed within this framework and supported by a number of policies and position statements including IAG's Social & Environmental Policy and Public Policy Position on Climate Change. Establish the future risk of Climate change to property and its impact financially for insurance companies. They have developed a climate change policy in order to deal with policies regarding the reporting and risks of climate change. 1
Brambles Limited 15 Very briefly discuss a reduction in carbon emissions through their production process. Further brief mentions in sustainability report. They are trying to reduce carbon emissions through their production process 1
QBE Insurance Group Limited 15 Zero mention in the annual report. Brief mention of climate change awareness and risk assessment in sustainability report. Acknowledge that climate change is real and a potential risk but not a major issue for them 0
AMP Limited 15 Very limited discussion. Only mention is of their aim to be environmentally conscious and that they have been carbon neutral since 2013. Not a large issue for them, aside from the fact that they have been carbon neutral since 2013. 0.5

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02/12/2017

El Niño Might Speed Up Climate Change

Scientific American - Tim Vernimmen

Scientists have evidence that El Niño boosts CO2 levels, and they are pinning down how
This picture taken on July 26, 2017 shows an Indonesian ranger inspecting the peat forest fire at Meulaboh, Aceh province. Credit: Chandeer Mayhuddin Getty Images
Every two to seven years, abnormally warm water in the Pacific Ocean causes an atmospheric disturbance called El Niño. It often makes extreme weather worse in various places around the world: greater floods, tougher droughts, more wildfires. Now scientists have new evidence indicating El Niño conditions might also add extra carbon dioxide to the atmosphere as well as lessen the ability of trees to absorb the greenhouse gas.
By certain measures, the most recent El Niño, which held sway in 2015 and 2016, was one of the three strongest on record, along with episodes in 1982–1983 and 1997–1998. Although its impacts on land were not clearly stronger than those of the other events, it appears it was the major culprit for a record increase in CO2 during its reign. “CO2 emissions from fossil fuels and industry did not really change from 2014 to 2016,” says climate scientist Pierre Friedlingstein at the University of Exeter in England, and an author of the 2017 carbon budget report released by the Global Carbon Project in November. So the dramatic increase, he says, must be due to how land and sea responded to El Niño.
A recent article in Science about satellite measurements made during El Niño by NASA’s Orbiting Carbon Observatory-2 showed most of the extra CO2 originated in the tropics. It also suggested each tropical region contributed a similar amount of CO2 as in other strong El Niño years, each in its own way. In South America's Amazon, for example, slower-growing plants absorbed less CO2, whereas in Africa, plants and soils released more of the gas.
The observations are based on satellite readings of CO2, carbon monoxide (which is released by wildfires) and other factors like the fluorescence of the chlorophyll in plant tissues (which reflects growth). But scientists would want some ground-truthing to prove El Niño conditions in the tropics boosted atmospheric CO2 levels. In the past, field data from plants and soils during an El Niño has been thin, but in 2015 researchers were better prepared.
Ecosystem scientist Yadvinder Malhi, at the University of Oxford, and colleagues analyzed data from 54 tropical forest plots in Ghana, Gabon, Malaysia, Brazil and Peru, which they presented at a recent meeting Mahli organized in London. The ground data confirmed what the satellite data had suggested: the tropics are key. The amount of CO2 released from the sites predicted the atmospheric levels “surprisingly well,” according to Malhi. “In contrast to long-term climate change,” he said at the meeting, “everybody agrees that El Niño makes the amount of CO2 in the atmosphere go up faster than usual.”
The next question was how much each continent contributed. Malhi says the Amazon appears to be the biggest player. “Africa always emits a lot of CO2, since it has a lot of wildfires, especially in the savannas. But its tropical forests and savannas didn’t behave very differently from other years,” he says. In the Amazon, however, “the emissions seemed largely due to respiration: CO2 released from plants, decaying logs and the soil.”
Further analysis will allow Malhi’s team to distinguish between those different sources, which is important for predicting longer-term impacts. If, for example, it turns out the extra CO2 released during El Niño is largely due to microbial activity in soils and decomposing plant material, Malhi says, “I wouldn’t expect it to last” as the world warms further. If the increase is coming from the plants because they are respiring more, that might be a signal of long-term stress that may continue to raise CO2 levels.
As a carbon booster, El Niño could hasten rising temperatures, bringing the world to dangerous thresholds sooner than thought. It could also enhance feedbacks between climate and vegetation that could reduce plants’ ability to absorb CO2 in non-Niño years as well. If bad droughts or wildfires kill many trees, for example, forests and their carbon sequestering potential may take centuries to recover, if ever.
Wildfires are a big concern. They were not quite as pervasive in 2015–2016 as they were in 1997–1998, when they were the most important global source of extra CO2. In 2015–2016, “a bit of rain at just the right moment prevented the Southeast Asian peat forest fires from spreading as widely as they did two decades ago,” says climate scientist Guido van der Werf at Vrije University Amsterdam. “Nevertheless, fire is a growing problem in the region.” Drought and heat make the forests more vulnerable. Wildfires release a lot of CO2, and they also eliminate the trees that might store more CO2 in the future.
Even in the absence of fire, El Niño might be killing trees. In northern Australia's remote Gulf of Carpentaria, more than 18,200 acres of mangrove vegetation died during the last El Niño due to a convergence of severe drought and unprecedented high temperatures. Death by drought may threaten trees in the Amazon as well.
To transport water from roots up to leaves, trees depend on tension created by the difference in water availability in the soil and the atmosphere, says plant physiologist Lucy Rowland at Exeter. “If it is very dry, however, that tension can get too high,” she says. “If that happens, the column of water in the trees’ transport vessels breaks. Then air gets in, blocking water flow like a bubble in your central heating system does.”
The only way trees can fix this problem is by growing new vessels—if the lack of water does not kill them first. Rowland is also investigating whether severe drought hampers the ability of tropical vegetation to absorb more CO2 as the atmospheric concentration rises. Right now, she says, the way climate models incorporate vegetation’s response to drought is too simplistic.
For now tropical trees appear to have returned to normal, their ecosystems absorbing more CO2 than they emit, Friedlingstein concludes. Unfortunately, man-made emissions have returned to their old status as well. “After two years of stability,” he adds, “they are going up again.”

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