Though his business card says Director of
Forest Carbon Science at The Nature Conservancy, Bronson Griscom
introduces himself as an ecological accountant. Griscom radiates an
optimism somewhat rare in seasoned environmentalists, especially when he
discusses the “carbon economy” of nature: the everyday role that trees,
grasslands and coastal habitats play in the carbon cycle. Griscom can
measure the carbon impact of logging in old growth forests, or how well
different forest ecosystems work as sinks for absorbing and storing
carbon from the atmosphere. He helps link our economy with the economy
of the biosphere.
In recent decades, forest use—Griscom’s area of expertise—has been widely studied for its climate impacts. Forest loss accounts for 8 to 10 percent of carbon emissions globally; tropical rainforests like the Amazon have become almost synonymous with land conservation, largely because they work as massive carbon sinks and are home to many of the world’s indigenous people and endangered species.
But other global ecosystems and managed lands—from farmlands and
peatlands to seagrass and tidal marshes—have garnered less attention
from climate regulators, both as a source of emissions and a potential
mitigation solution. In fact, until recently no one had ever integrated
the raw data on all the carbon that all ecosystems were already
sequestering, and what the potential was for increasing carbon storage
among all these habitats together, as Griscom and his team studied.
“I thought we would review a few papers and take an average to answer
the question,” he says. “We were shocked to find that important gaps
remained in answering the question: how much can lands contribute to
solving climate change? So we took it upon ourselves to convene a large
group of scientists across 15 research institutions to take a
comprehensive look at this question.”
Answering that question
became the highest priority for Bronson’s team, and the foundation for
what has become the most comprehensive study on the role that nature can
play in keeping global temperature increases to 2°C or below. They found that,
with the right management, nature can play a bigger role than we
Video: What are Natural Climate Solutions?
Natural climate solutions offer up to 37% of the mitigation needed between now and 2030 to keep global temperature rise below 2°C.
Published on October 16 in the Proceedings of the Natural Academy of the Sciences, the paper offers a comprehensive roadmap for reducing carbon emissions through nature. The study is the culmination of a partnership between the Conservancy and the Doris Duke Charitable Foundation that brought together more than two-dozen leading natural scientists and economists from fifteen research, educational and private institutions around the world.
The land-use sector is currently responsible for a quarter of greenhouse gas emissions. But this new study shows that this could change—and with concerted global action on land use over the next decade, nature can be a significant part of the climate solution.
The analysis found that the total biophysical potential for natural climate solutions while still taking account of food production needs is as much as 23.7 billion tons of carbon dioxide equivalent per year—approximately 30 percent more than previous, less comprehensive estimates.
In addition, the study’s economic analyses show that half of these natural climate solutions (11.3 billion tons CO2e) offer cost-effective mitigation opportunities, because they cost less than the future impacts of climate change, expected to cost society more than $100 per ton of CO2 in the atmosphere. These cost-effective NCS mitigation options offer up to 37 percent of mitigation needed between now and 2030 to keep global temperature rise below 2°C —the widely recognized target of the Paris Climate Agreement.
Pathways to Natural Climate Solutions
synthesize the research, Griscom and his team developed a framework to
distill the world’s “natural climate solutions”—the proven ways of
storing and reducing carbon emissions in forests, grasslands (including
agricultural and rangelands) and wetlands—into a taxonomy of 20 specific
pathways that account for the full climate potential of nature.
In addition to covering three biomes, the pathways also look at different practices across a variety of economic scenarios that mitigate climate change, including the implementation of low-cost opportunities only ($10 per tonne CO2e or less).
Another striking aspect of these pathways is the additional benefits they provide. Most nature climate solutions—if effectively implemented—also offer water filtration, flood buffering, improved soil health, protection of biodiversity habitat, and enhanced climate resilience.
“The approach is synergistic,” says Justin Adams, managing director for Global Lands at the Nature Conservancy. “We can hit multiple targets of the UN Sustainable Development Goals if we get this right.”
There is, however, a catch: The world must act soon.
Infographic - 20 Pathways of Natural Climate Solutions
Reproduced with permission from Proceedings of the National Academy of Science.
Assuming current business-as-usual trajectories, increased emissions entering the atmosphere, coupled with continued environmental degradation, will lessen the impact that nature can have. If natural climate solutions are mobilized over the next 10 to 15 years, they could provide 37 percent of the needed mitigation for global climate targets. But if action is delayed until after 2030, that number drops to 33 percent, and drops again to only 22 percent after 2050.
Over the past two years, the world experienced unprecedented global
climate momentum. In September 2015, international leaders adopted the
UN’s 17 Sustainable Development Goals, which aim to fight poverty,
promote sustainability and address climate change. Shortly after, nearly
200 countries came together in Paris to adopt the world’s largest ever
international climate treaty.
And despite recent setbacks,
including the United States announcing its intention to withdraw from
the Paris Agreement, many countries have moved forward implementing
voluntary measures to limit emissions. And while natural climate
solutions are part of many countries’ pledges, there remains a gap between
promised action and realized climate progress.
"Natural climate solutions are available now, are cost effective and greatly benefit communities."
As they are currently written, the Paris Agreement pledges still fall short, likely keeping warming around 4°C. Every five years, international representatives and negotiators will meet to ramp up ambition, but the current timeline for countries to end their reliance on fossil fuels while still maintaining development and economic growth does not align with what is needed to achieve climate stability. Barring a technological miracle, the world likely needs more time than it realistically has to move to full economic decarbonization.
“There’s a growing recognition that to get to below 2°C, we need to actively drawdown carbon from the atmosphere,” Adams says. “And while there’s lots of interest and investment in new technology solutions to capture and store carbon, this is new, experimental technology. Trees and other plants, meanwhile have already perfected this process over hundreds of millions of years of evolution—we’re unlikely to see a better carbon capture and storage technology than that which nature provides.”
This makes the findings from the 20 pathways particularly important:
they provide a scalable near-term option that, combined with fossil fuel
emission reductions, can put the planet on a 2° path by 2030. If world
leaders hold off on concurrently investing in nature now, emerging
technology will have to play an exponentially larger role in reducing
emissions later on. “That’s a gamble on the future that can be prevented
today,” Adams says.
“The rapid deployment of clean energy
technologies currently being witnessed is truly inspiring, and we
absolutely must press forward with the deployment of renewables,
electric cars, energy efficiency and other methods for fossil fuel
reduction,” Adams adds. “But we also need to see a similar level of
investment in natural solutions, which are available now, are cost
effective and greatly benefit communities.”
Investing Where It Counts
To understand some of the challenges to implementing natural climate solutions, consider the case of Indonesia. The country holds the world’s third largest tropical rainforest, but it has also experienced some of the fastest forest loss in tropical countries, primarily due to increased palm oil and forestry activities. The destruction of tropical forest ecosystems accounts for almost 50 percent of Indonesia's emissions, contributing to Indonesia’s position as the world’s tenth top emitter of greenhouse gasses.
At the same time, “development is a required process for Indonesia,” says Wahjudi Wardojo, The Nature Conservancy’s senior advisor for terrestrial policy in Indonesia. Any conservation efforts in Indonesia need to balance economic growth with sustainable development.
Wardojo is not alone in this situation—change agents working across widely different constituencies, ecosystems and governments face similar obstacles in implementing natural climate solutions. To convince land managers in both the public and private sector, they need more and better economic data that communicates the financial opportunities in deploying natural climate solutions.
It’s this universal need for strong science and economic data that
Adams, Griscom and the study’s co-authors hope to support. The research
and findings in “Natural Climate Solutions” can be used as a starting
point to guide cost-effective implementation of the 20 natural pathways
around the world.
Land-based climate solutions appear in more than
75 percent of individual country commitments to the Paris Agreement, yet renewable energy, energy efficiency and clean transport together receive nearly 30 times the amount of public mitigation investment that land-based solutions receive. Of the funding
that is set aside for natural climate solutions, the vast majority
tends to focus on tropical forest protection in developing countries.
Globally, forest pathways offer about half of the lowest-cost climate opportunities, while grassland and agriculture pathways account for a quarter, and wetlands nearly a fifth. But depending on a country’s geography and economy, any of these pathways could be significant for reducing emissions.
“The important thing is for people to realize that this isn’t pie in the sky. Natural climate solutions are real techniques that have climate value,” says Bill Schlesinger, former president of the Cary Institute of Ecosystem Studies. “The guts of the paper are the economic graphs which tell us under different economic scenarios what is realistically possible.”
"Biodiversity loss in the wetlands and rainforests, nutrient-rich soil issues for farmers, indigenous people’s forest rights ... it’s all connected."
the coalitions needed to implement these solutions, even the most
cost-effective ones, is easier said than done, especially if we’re to
take action in the next decade. But one striking aspect of this new
study is its demonstration that sectors often viewed as part of the
problem—in particular forestry and agriculture—have a huge opportunity
to step up and work as partners to transform working lands from carbon
emitters to carbon sinks.
Around the world and in a variety of ecosystems, efforts such as
these are already seeing wide-scale success. In Indonesia, for example,
advances in reduced-impact logging techniques are helping to mitigate
carbon emissions even as the timber industry continues to support
economic growth. From farmers in Northern Africa fighting
desertification by planting trees to New Guinean fishing communities
planting mangroves to attract fish and store carbon, there are thousands
more on-the-ground projects setting the foundation for what is
If actions are taken now, nature can be an ally for sustainable
development, economic growth and a low-carbon future—a future, as Adams
puts it, where people and nature can thrive together.
Additional Case Studies
See more case studies demonstrating natural climate solutions in action.
This symbiotic approach to conservation and climate work is increasingly resonating with international leaders and unexpected partners in the climate community. And while the world is still a long way from the level of private sector investment and government action needed for natural climate solutions to reach transformational scale, there’s an air of excitement surrounding those who work in this space.
“It’s incredible that to solve this relatively new problem—that seems bigger and uglier than anything we’ve ever tackled—we can also help solve other environmental challenges,” Bronson says. “Biodiversity loss in the wetlands and rainforests, nutrient-rich soil issues for farmers, issues surrounding indigenous people’s forest rights, and so on. Cue the 'Lion King' song—it’s all connected.”
Griscom’s positivity is contagious, but current climate projections
provide a sobering reminder that even committed global climate actions
are not yet enough to avoid the catastrophic effects of a warming
planet. If the world does not keep global temperatures from rising above
2°C, the World Bank
warns of “extreme heat-waves, declining global food stocks, loss of
ecosystems and biodiversity, and life-threatening sea level rise," the
effects of which will hit hardest in the world’s poorest regions, as is already being seen.
can not hit the 2°C or below target through reforms in the energy,
industrial and transportation sectors alone, Griscom says—preventing
further loss of nature and investing in natural climate solutions are
essential to climate stability. The good news is these opportunities are
both abundant and come a broad array of other benefits. This is
climate’s make or break moment, and, as Griscom puts it, “nature is the
Report: Lands of Opportunity
For a more comprehensive exploration of strategies for implementing natural climate solutions, download Lands of Opportunity: Unleashing the Full Potential of Natural Climate Solutions.