Restoring tree cover is now firmly established as a strategy for removing carbon from the atmosphere to help tackle climate change.
But there is an elephant in the room when it comes to estimating just how promising a climate solution it is in different locations. This is “albedo” – the fraction of the solar radiation that is reflected from the Earth’s surface.
In essence, brighter surfaces – such as a large snowy expanse or a grassland – will generally reflect a high proportion of sunlight back into space. Trees, meanwhile, tend to be darker coloured and absorb more sunlight, keeping it on Earth – usually in the form of excess heat.
Because restoring tree cover often involves replacing brighter land covers – such as grasslands – with darker ones – namely, trees – this can lead to some degree of global warming.
In some locations, this warming can partially or even completely outweigh the benefit of increased carbon uptake by the trees. Many know of this problem, but it has been difficult to quantify the impact of albedo in specific locations.
In our new study, published in Nature Communications, we map albedo change from restoring tree cover and show that carbon-only estimates of the global climate benefits of tree-planting may be 20-81% too high.
Our maps reveal that the climate benefits of tree-planting in savannahs in Africa and central Asia would be the most reduced by albedo. But we show that it is possible to find places that provide net-positive climate mitigation benefits in all biomes.
Tree cover affects albedo
It is getting harder to ignore albedo when planning projects to restore tree cover for climate mitigation.
For example, a recent study published in Science showed that albedo, among other factors, could substantially reduce the climate mitigation benefit of restoring tree cover.
However, despite its importance, albedo is often only given a brief mention as an important factor in research attempting to quantify the climate benefits of restoring tree cover. Its impact is frequently not accounted for – or only via coarse adjustments.
In some places, restoring tree cover modifies albedo enough to dwarf smaller changes in carbon, leading to an overall (net) increase in global warming. In other locations, the impact of albedo does not outweigh the carbon removal, contributing to an overall global cooling effect.
Understanding and quantifying these variations in albedo and carbon change is crucial to the success of a project that aims to restore tree cover for climate mitigation.
Yet there has been a lack of tools to provide this information. Our study sets out to change that.
Mapping albedo change
Our study provides the maps that quantify the absolute and relative changes in albedo anywhere on Earth where we might grow trees.
We first created a series of 24 maps that quantified how albedo would change if an area transitioned from one of four open land cover classes – such as grassland or croplands – to one of six different forest-cover classes, such as deciduous broadleaf or evergreen needleleaf forest. These are useful for individual projects that know their starting and end conditions.
However, to examine general global patterns, we used a data-driven approach to model the albedo change resulting from the “most likely” open-to-forest transition for each part of the world. We then combined that with a map of maximum potential carbon storage to map net climate impact in carbon dioxide equivalents.
In this map (below), red and orange shading indicates regions where restoring tree cover leads to net warming and blue indicates regions where restoring tree cover leads to net cooling.
The map shows that, in many places, increasing tree cover is likely to contribute to global warming. These include the dryland ecosystems of central Asia and the Sahel region of Africa, as well as northern reaches of North America, Europe and Asia.
However, all biomes had at least some climate-positive locations, indicating that the coarse exclusions used in the past have missed opportunities. Moreover, some locations experience little to no albedo change, such as in south-east Asia, central Africa and the Amazon.
This map makes it possible for people to determine the best places to restore tree cover to achieve climate mitigation, as well as evaluate different scenarios of where restoration of tree cover might happen.
For example, we examined three previously published global studies of large-scale increases in tree cover. We find that, after accounting for albedo, the global climate mitigation benefit of restoring tree cover may actually be 20-81% lower than expected from carbon-only estimates.
Notably, the study with the greatest deduction included large areas of tree-planting within the tundra and other locations where we predict very negative climate outcomes. We show that constraining this study’s tree-planting to only the more climate-positive areas – about a third of the total area (311m hectares instead of 889m hectares) – would lead to a 2.5-fold increase in mitigation potential.
This demonstrates the value of strategic project placement to maximise climate benefit, because it is possible to achieve more mitigation with less investment of space.
Forest restoration projects
Encouragingly, our study also finds that hundreds of thousands of on-the-ground tree-planting projects tend to be concentrated in places where the potential for carbon removal is high and albedo change is moderate.
One example is the moist tropical ecosystems in Brazil and Indonesia. Most of these on-the-ground projects can be found at Restor, a data-driven and community-based platform that aims to accelerate restoration and makes it possible for the first time to evaluate outcomes of the global restoration movement.
This suggests that ongoing or planned projects are concentrated in places that are good for achieving climate mitigation. However, the majority – around two-thirds – of these on-the-ground projects still face an albedo offset of at least 20%, indicating that most – if not all – projects should consider albedo change in their accounting.
None of this is to criticise projects that fall in places with negative climate outcomes. There are many wider reasons for restoring tree cover in a given landscape, beyond climate mitigation, including cleaner water, wildlife habitat, stabilised soils, sustainable livelihoods and cooler local temperatures.
However, for projects where the emphasis is on achieving climate mitigation, it is important to consider changes in albedo alongside changes in carbon removal, especially now that the tools are available to do so.
In general, climate accounting is not for the faint of heart. There are many factors such as albedo that can alter the total climate mitigation of natural climate solutions. However, we are in a critical time when pragmatic decisions need to be made now about which climate solutions to deploy and where.
Alongside our study, we have produced a dedicated web platform – called “naturebase” – to help policymakers, practitioners, communities and governments identify where, why and how to implement nature-based projects with the highest carbon mitigation.
This tool includes maps, data and case studies to show how different natural climate solutions – including restoration of tree cover – could benefit the climate across the world.
Policymakers and land managers are under growing pressure to make complex choices in line with global agreements. We hope that the science in our study and the tools in the naturebase platform will help enable smarter, more nature-positive decisions.
The post Guest post: Mapping where tree-planting has the greatest climate benefit appeared first on Carbon Brief.
Guest post: Mapping where tree-planting has the greatest climate benefit
Casting doubt on the determination that greenhouse gas emissions endanger public health and welfare, he said, “we’re not accepting all of the narrative of the left without any question or pushback.”
WASHINGTON—Addressing a conference of scientists and other experts skeptical of climate change, Environmental Protection Agency Administrator Lee Zeldin on Wednesday celebrated his decision to repeal what is known as the “endangerment finding,” which provided the backbone for federal regulation of greenhouse gas emissions.
Zeldin Celebrates Endangerment Finding Repeal With Climate Skeptics
With the U.S. bombing Iran and the Strait of Hormuz closed, energy experts say countries transitioning to renewables will be more resilient in the “face of the shock.”
The United States’ war on Iran could fundamentally alter how countries consume and generate energy and hamper international progress in combating climate change, a panel of energy experts said today.
The Global Energy Supply in a Decade ‘Is Not a World We’re Going to Recognize’
One month into the US and Israel’s war on Iran, at least 60 countries have taken emergency measures in response to the subsequent global energy crisis, according to analysis by Carbon Brief.
So far, these countries have announced nearly 200 policies to save fuel, support consumers and boost domestic energy supplies.
Carbon Brief has drawn on tracking by the International Energy Agency (IEA) and other sources to assess the global policy response, just as a temporary ceasefire is declared.
Since the start of the war in late February, both sides have bombed vital energy infrastructure across the region as Iran has blocked the Strait of Hormuz – a key waterway through which around a fifth of global oil and liquified natural gas (LNG) trade passes.
This has made it impossible to export the usual volumes of fossil fuels from the region and, as a result, sent prices soaring.
Around 30 nations, from Norway to Zambia, have cut fuel taxes to help people struggling with rising costs, making this by far the most common domestic policy response to the crisis.
Some countries have stressed the need to boost domestic renewable-energy construction, while others – including Japan, Italy and South Korea – have opted to lean more on coal, at least in the short term.
The most wide-ranging responses have been in Asia, where countries that rely heavily on fossil fuels from the Middle East have implemented driving bans, fuel rationing and school closures in order to reduce demand.
‘Largest disruption’
On 28 February, the US and Israel launched a surprise attack on Iran, triggering conflict across the Middle East and sending shockwaves around the world.
There have been numerous assaults on energy infrastructure, including an Iranian attack on the world’s largest LNG facility in Qatar and an Israeli bombing of Iran’s gas sites.
Iran’s blockade of the Strait of Hormuz, a chokepoint in the Persian Gulf, is causing what the IEA has called the “largest supply disruption in the history of the global oil market”.
A fifth of the world’s oil and LNG is normally shipped through this region, with 90% of those supplies going to destinations in Asia. Without these supplies, fuel prices have surged.
Governments around the world have taken emergency actions in response to this new energy crisis, shielding their citizens from price spikes, conserving energy where possible and considering longer-term energy policies.
Even with a two-week ceasefire announced, the energy crisis is expected to continue, given the extensive damage to infrastructure and continuing uncertainties.
Asian crunch
Carbon Brief has used tracking by the IEA, news reports, government announcements and internal monitoring by the thinktank E3G to assess the range of national responses to the energy crisis roughly one month into the Iran war.
In total, Carbon Brief has identified 185 relevant policies, announcements and campaigns from 60 national governments.
As the map below shows, these measures are concentrated in east and south Asia. These regions are facing the most extreme disruption, largely due to their reliance on oil and gas supplies from the Middle East.
Nations including Indonesia, Japan, South Korea and India are already spending billions of dollars on fuel subsidies to protect people from rising costs.
At least 16 Asian countries are also taking drastic measures to reduce fuel consumption. For example, the Philippines has declared a “state of national emergency”, which includes limiting air conditioning in public buildings and subsidising public transport.
Other examples from the region include the government in Bangladesh asking the public and businesses to avoid unnecessary lighting, Pakistan reducing the speed limit on highways and Laos encouraging people to work from home.
Europe – which was hit hard by the 2022 energy crisis due to its reliance on Russian gas – is less immediately exposed to the current crisis than Asia. However, many nations are still heavily reliant on gas, including supplies from Qatar.
The continent is already feeling the effects of higher global energy prices as countries compete for more limited resources.
At least 18 European nations have introduced measures to help people with rising costs. Spain, which is relatively insulated from the crisis due to the high share of renewables in its electricity supply, nevertheless announced a €5bn aid package, with at least six measures to support consumers.
Many African countries, while also less reliant on direct fossil-fuel supplies via the Strait of Hormuz than Asia, are still facing the strain of higher import bills. Some, including Ethiopia, Kenya and Zambia, are also facing severe fuel shortages.
There have been fewer new policies across the Americas, which have been comparatively insulated from the energy crisis so far. One outlier is Chile, which is among the region’s biggest fuel importers and is, therefore, more exposed to global price increases.
Tax cuts
The most common types of policy response to the energy crisis so far have been efforts to protect people and businesses from the surge in fuel prices.
At least 28 nations, including Italy, Brazil and Australia, have introduced a total of 31 measures to cut taxes – and, therefore, prices – on fuel.
Even across Africa, where state revenues are already stretched, some nations – including Namibia and South Africa – are cutting fuel levies in a bid to stabilise prices.
Another 17 countries, including Mexico and Poland, have directly capped the price of fuel. Others, such as France and the UK, have opted for more targeted fuel subsidies, designed to support specific vulnerable groups and industries.
These measures are all shown in the dark blue “consumer support” bars in the chart below.
Such measures can directly help consumers, but some leaders, NGOs and financial experts have noted that there is also the risk of them driving inflation and reinforcing reliance on the existing fossil fuel-based system.
Christine Lagarde, president of the European Central Bank, spoke in favour of short-term measures to “smooth the shock”, but noted that “broad-based and open-ended measures may add excessively to demand”.
Measures to conserve energy, of the type that many developing countries in Asia have implemented extensively, have been described by the IEA as “more effective and fiscally sustainable than broad-based subsidies”.
So far, there have been at least 23 such measures introduced to limit the use of transport, particularly private cars.
These include Lithuania cutting train fares, two Australian states making public transport free and Myanmar and South Korea asking people to only drive their cars on certain days.
Clean vs coal
At least eight countries have announced plans to either increase their use of coal or review existing plans to transition away from coal, according to Carbon Brief’s analysis. These include Japan, South Korea, Bangladesh, the Philippines, Thailand, Pakistan, Germany and Italy.
These measures broadly involve delaying coal-plant closure, as in Italy, or allowing older sites to operate at higher rates, as in Japan – rather than building more coal plants.
There has been extensive coverage of how the energy crisis is “driving Asia back to coal”. However, as Bloomberg columnist David Fickling has noted, this shift is relatively small and likely to be offset by a move to cheap solar power in the longer term.
Indeed, some countries have begun to consider changes to the way they use energy going forward, amid a crisis driven by the spiralling costs of fossil-fuel imports.
Leaders in India, Barbados and the UK have explicitly stressed the importance of a structural shift to using clean power. Governments in France and the Philippines are among those linking new renewable-energy announcements with the unfolding crisis.
New renewable-energy capacity will take time to come online, albeit substantially less time than developing new fossil-fuel generation. In the meantime, some nations are also taking short-term measures to make their road transport less reliant on fossil fuels.
For example, the Chilean government has enabled taxi drivers to access preferential credit for purchasing electric vehicles (EVs). Cambodia has cut import taxes on EVs and Laos has lowered excise taxes on them.
Finally, there have been some signs that countries are reconsidering their future exposure to imported fossil fuels, given the current economics of oil and gas.
The New Zealand government has indicated that a plan to build a new LNG terminal by 2027 now faces uncertainty. Reuters reported that Vietnamese conglomerate Vingroup has told the government it wanted to abandon a plan to build a new LNG-fired power plant in Vietnam, in favour of renewables.
The post Iran war analysis: How 60 nations have responded to the global energy crisis appeared first on Carbon Brief.
Iran war analysis: How 60 nations have responded to the global energy crisis
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