Climate 411

Resolving scientific uncertainties in nature-based climate solutions: Location, location, location

By Doria Gordon / Published: March 21, 2024
Drone shot of mangrove trees off the coast of the Yucatán Peninsula in Mexico.

Drone shot of mangrove trees off the coast of the Yucatán Peninsula in Mexico. Carlos Aguilera / EDF Mexico

The world needs nature-based climate solutions (NbCS). These approaches use conservation, restoration, and management of natural and agricultural systems to retain existing, and sequester additional, carbon while reducing emissions of CO2 and other greenhouse gases. NbCS have been suggested to meet 20-30% of the world’s climate goals. Correspondingly, nature-based actions are included in the national commitments of 63% (104 of 168) of the signatories of the Paris Agreement.

However, defining the climate impact of different solutions requires accurate scientific measurement and accounting of greenhouse gas mitigation, including how long that benefit lasts. Where we lack accurate measurements and estimates of future durability, we cannot yet rely on NbCS to meet our climate goals.

Assessment of the science on NbCS
Environmental Defense Fund recently worked with experts in academia and other conservation and research institutions to assess the scientific confidence in more than 40 NbCS that have been proposed. The results of that inquiry are both optimistic and sobering.

The four most frequently credited NbCS by the four major carbon credit registries have high scientific confidence – tropical and temperate forest avoided conversion or degradation and reforestation. The confidence of the scientific community in those NbCS supports investing in these as climate solutions and demonstrates that we can develop sufficient understanding of process, measurement, and accounting methods necessary to meet high quality crediting requirements.

However, the experts concluded that 90% (39/42) of the proposed NbCS assessed in the study currently have insufficient scientific evidence for having climate impact we can count on. Within that 90% are NbCS like avoided conversion and degradation of systems as different as mangroves and boreal forests (see below for why).

Promisingly, the experts do have confidence that we can remedy this situation: focused research over the next five years could resolve many of the remaining questions for two-thirds of those pathways. Given that some, like agroforestry, tropical peatland conservation, and biochar additions are also estimated to have large-scale climate impacts, this study provides a roadmap for prioritizing research efforts.

The importance of location
Every NbCS is different, and so are the specific uncertainties and research needs. Prediction of how natural systems may change as the climate changes – affecting their carbon storage and greenhouse gas emissions – is inherently uncertain. We are better at modeling some systems (like tropical forests) than others (like seagrass beds). But all NbCS pathways have something in common – location matters.

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Also posted in Basic Science of Global Warming, Carbon Markets, Forest protection, Greenhouse Gas Emissions, News, Oceans, Science / Comments are closed

Unlocking the planet-saving potential of crediting natural climate solutions

By Devyani Singh / Published: April 22, 2022

With contributions from Julia Paltseva, senior analyst, Britta Dosch, analyst, and Christine Gerbode, senior research analyst, all at Environmental Defense Fund. 

Gardens of the Queen archipelago off the coast of Cuba

Earth’s forests, oceans, wetlands and other natural landscapes have the power to pull carbon out of the atmosphere and to store it – making well-managed ecosystems key resources in the fight to halt climate change. The latest report from the Intergovernmental Panel on Climate Change found protecting these resources offers one of the highest mitigation potentials.

Efforts to keep healthy ecosystems intact, restore those that have been cleared or degraded, and improve how these landscapes are managed can have huge benefits to people and the planet, like improving water quality or protecting biodiversity. When these efforts also increase carbon storage or avoid greenhouse gas emissions, they are known as natural climate solutions, or NCS.

Healthy ecosystems around the world are disappearing rapidly, as more of the planet is degraded or converted to other uses. This continued loss could have dire consequences for the entire globe through its effect on climate, while doing particular harm and injustice to the Indigenous and local communities who have historically stewarded many of these crucial environments.

Scaling up global funding and support for NCS activities is an opportunity to limit climate damage while enhancing and protecting the enormous good these ecosystems provide – and benefiting the local people carrying out these important tasks.

One way to do this is to incorporate NCS activities into global carbon markets by crediting emissions. Environmental Defense Fund is now leading a collaborative process to lay out the key considerations and challenges of supporting NCS with the potentially powerful tool of crediting emissions reductions and removals—and of making sure the systems to support this tool are ethical, equitable and effective at the much larger scales of ambition needed to meet the moment.

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Also posted in Carbon Markets, Forest protection, Indigenous People / Comments are closed

A Holiday Gift for the Environment – New Tools to Fight Invasive Species

By Doria Gordon / Published: December 20, 2016
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Kudzu in Atlanta, GA – one of many invasive species in the U.S. Photo by Scott Ehardt through Wikimedia Commons

The environment got an early gift this holiday season.

The Obama Administration has just released an update to an Executive Order first developed in 1999 on safeguarding the nation from the impacts of invasive species.

If you’ve ever lived in Florida, like I used to, you’ve seen the danger of invasive species first-hand. Whether it’s the nasty bites of fire ants, or the incessant need to control weedy invaders that threaten to overtake the landscape, or the menace of invasive snakes in the Everglades, invaders interfere everywhere.

Florida is just one of the many places around the U.S. where it’s hard to ignore the impacts of invasive, non-native species on everyday life. If you are a farmer or a rancher or enjoy fishing or boating or birdwatching, invaders can be an expensive problem, a health threat, and a substantial inconvenience. Invaders cost the U.S. billions of dollars annually and pose significant threats to our health and livelihoods.

As a plant ecologist, I started by learning where these non-native species are coming from. They can arrive accidentally – as hitchhikers on other imports or the packing material those imports are shipped in – or purposely – for food, ornamentals, pets, or other uses like erosion control. My investigation into plant invaders showed that the vast majority – perhaps 90 percent – were purposely introduced.

That information led me to focus on how we might prevent the introduction of new invaders, through risk analyses and other methods. Over the years, our ability to identify the likely bad actors – whether they are plant, animal, insect, or disease – has really improved.

That brings me back to the updated Executive Order.

The main emphasis of the original Executive Order was to ensure coordinated action among the federal agencies to prevent new invaders and control existing ones, as well as to work in partnership with the private sector to achieve these goals.

In addition to reinforcing and strengthening the original intent of the Order, this update emphasizes that human and environmental health need protection, and that those efforts will be impacted by climate change. The updated Order also recognizes that the need to seek and take advantage of technological advances for both prevention and management or control of invaders.

The updated Executive Order was announced on the same day that an Innovation Summit on new potential options for addressing invasive species was held. I had the chance to attend that summit.

In addition to hearing about approaches to control species ranging from fish to plant and human diseases (including some very cool new methods for detection and control), presenters discussed how to incentivize innovation around this issues. Summit presentations showed that the advances called for in the updated Executive Order are emerging, providing an optimistic outlook for all of us concerned about this issue.

Because invaders don’t respect property boundaries and don’t stay put, we need everyone to join the effort to stop their import and movement. News of the Zika virus in the U.S., carried by a non-native mosquito that also carries at least four other diseases, is a clear indicator of the need to take aggressive action. So the Obama Administration’s decision to update the Executive Order is a great holiday gift for all of us.

Also posted in News, Science / Comments are closed

The Impacts of Climate Change on Human Health – a Sobering New Report

By Ilissa Ocko / Published: April 5, 2016

We have even more information this week about the ways climate change poses a threat to human health.

The U.S. Global Change Research Program just released its newest report—The Impacts of Climate Change on Human Health in the United States. This scientific assessment is the culmination of three years of work by hundreds of experts, and builds on the more general National Climate Assessment released in 2014.

The report concludes that every American is vulnerable to the health impacts associated with climate change.

Health Threats from Climate Change graphic

Graphic created by Ilissa Ocko, EDF Scientist

Scientists have known for decades that climate change threatens human health via excessive heat, worsened air quality, water related illnesses, food safety, diseases transmitted by pests like fleas and mosquitos, and mental stress. The new report thoroughly characterizes our current understanding of these impacts.

Because scientific understanding has advanced significantly in recent years, the authors also reviewed new information and insights from several recent scientific, peer-reviewed publications and other publicly available resources.

For example, new data revealed that the Ragweed season has grown by as much as 27 days in the central U.S. from 1995 to 2011, and the incidence of Lyme disease in the Northeast has doubled from 2001 to 2014, both consistent with warming trends.

Recent modeling studies have also improved quantification estimates of and confidence in projected health outcomes from climate change. By midcentury, scientists project that there will be as many as thousands of additional ground-level ozone (smog) related illnesses and premature deaths, and the majority of the western U.S. will have a 500 percent  increase in the number of weeks with risk of very large fires. By the end of the century, scientists project that there will be an additional 27,000 summertime heat-related deaths annually in over 200 U.S. cities (that are currently home to 160 million people), and harmful toxin-producing algal blooms could develop up to two months earlier and persist for up to two months longer.

Through climate and weather changes and disruptions to ecosystems and societal systems, here are the main concerns about climate change impacts on human health:

  • Temperature Related Death and Illness — Future climate warming could cause up to tens of thousands of additional deaths each year from heat in the summer, from loss of ability to control internal temperature, and worsened chronic cardiovascular and respiratory diseases
  • Air Quality Impacts — The future could include limited productivity at work and school due to exacerbated ground-level ozone (smog) health impacts from modified weather patterns conducive to ozone formation, and worsened allergy and asthma conditions from more airborne pollen and longer pollen seasons
  • Vectorborne Disease — The seasonality, distribution, and prevalence of vectorborne diseases, including Lyme disease and West Nile virus,  may change with changing temperature and rainfall patterns due to altered geographic and seasonal distributions of mosquitoes, ticks, and fleas
  • Water-Related Illness — Risk of exposure to illnesses increases as the growth, survival, spread, and toxicity of water-related pathogens and toxins is impacted by temperature and extreme rainfall events, and aging water infrastructure is vulnerable to failure with extreme events and storm surges
  • Food Safety, Nutrition, and Distribution — Rising temperatures, changing weather patterns, and extreme events have consequences for contamination, spoilage, and the disruption of food distribution, whereas higher carbon dioxide levels lower nutritional value of crops despite boosting plant growth
  • Extreme Weather — Fatalities, injuries, and infrastructure damages are imminent with increases in the frequency and/or intensity of extreme precipitation, hurricanes, coastal inundation, drought, and wildfires
  • Mental Health and Well-Being — Mental health conditions may develop with exposure to disasters or worsen by extreme health

Overall, the report is a sobering portrait of the risks we face because of climate change — and it underscores the urgency for climate action.

 

 

 

Also posted in Basic Science of Global Warming, Extreme Weather, Health, News, Science / Comments are closed

3 reasons the Zika outbreak may be linked to climate change

By Ilissa Ocko / Published: February 17, 2016

The regions that the Zika virus outbreak has struck hardest, such as Brazil and Colombia, also happen to be areas that are currently plagued by hotter-than-usual temperatures.

So is there a connection?

The ways that virus-carrying mosquitoes change their behavior with warmer temperatures may, in fact, point to a link between the Zika outbreak and climate change like the one that exists with malaria, Lyme Disease and other ills.

While it’s important to remember that it’s probably a combination of reasons for the current Zika virus outbreak – including movement of people and available breeding grounds – there are three ways in particular that warmer weather may be contributing to the crisis:

graphic_v3 (2)

1. Hotter temperatures make mosquitoes hungrier

Female mosquitoes require blood meals for reproduction. Along with many cold-blooded animals, mosquitoes feed more frequently with higher temperatures. The more they eat, the likelier they are to get infected and spread the disease.

2. Warm air incubates the virus faster

A virus must incubate inside a mosquito before the mosquito becomes infectious. That takes about 10 days, roughly a mosquito’s lifespan, so the mosquito will often die before it can spread the disease.

But hotter temperatures speed up the incubation process in the cold-blooded mosquito, because the virus can replicate faster. This means that the mosquito will be alive longer while infectious, thus having more time to transmit the disease.

3. Mosquito territory expands as the climate warms

Mosquitoes flourish in warm climates, restricting their range based on temperature. But with climate change, plants and animals are moving northward and upward, and we know mosquitoes do the same as new areas become warmer and a suitable habitat.

As mosquitoes expand their range, they can introduce diseases to populations that otherwise would have been safely out of reach. The distribution of the Zika-carrying mosquito, in particular, has wildly increased over the past few decades, which have also been the hottest decade on Earth in more than 1,000 years.

In fact, the current epidemic took off in 2015, the hottest year in South America and globally since record-keeping began 136 years ago.

The links between mosquitoes and temperature are scientifically clear, and it’s possible that climate change may now be playing a role in the spread of the Zika virus, a disease suspected of causing serious birth defects.

To know for sure, and to help nations deal with the outbreak, more research is needed to tease out the specific causes of this global catastrophe.

This post originally appeared on our EDF+Voices blog.

Also posted in Health, News, Science / Comments are closed

Six Climate Tipping Points: How Worried Should We Be?

By Ilissa Ocko / Published: June 17, 2015

One of the biggest fears about climate change is that it may be triggering events that would dramatically alter Earth as we know it.

Known to scientists as “tipping events,” they could contribute to mass extinction of species, dramatic sea level rise, extensive droughts and the transformation of forests into vast grasslands – among other upheavals our stressed world can ill afford.

Here are the top six climate events scientists worry about today.

1. The Arctic sea ice melts

The melting of the Arctic summer ice is considered to be the single greatest threat, and some scientists think we’ve already passed the tipping point.

As sea ice melts and the Arctic warms, dark ocean water is exposed that absorbs more sunlight, thus reinforcing the warming. The transition to an ice-free Arctic summer can occur rapidly – within decades – and this has geopolitical implications, in addition to a whole ecosystem being disrupted.

Photo: Smudge 900)

2. Greenland becomes ice-free

The warming of the Arctic may also render Greenland largely ice-free. While Greenland’s ice loss will likely reach the point of no return within this century, the full transition will take at least a few hundred years.

The impacts of the Greenland ice melt is expected to raise sea levels by up to 20 feet.

Half of the 10 largest cities in the world, including New York City, and one-third of the world’s 30 largest cities are already threatened by this sea level rise. Today, they are home to nearly 1.8 billion people.

Other vulnerable American cities include Miami, Norfolk and Boston.

Photo: siralbertus

3. The West Antarctic ice sheet disintegrates

On the other side of Earth, the West Antarctic ice sheet is also disintegrating. Because the bottom of this glacier is grounded below sea level, it’s vulnerable to rapid break-up, thinning and retreat as warm ocean waters eat away at the ice.

Scientists expect the West Antarctic ice sheet to “tip” this century, and there is evidence that it already began happening in 2014.

However, the entire collapse of the glacier, which would raise sea level by 16 feet, could take a few hundred years.

Photo: BBC World Service

4. El Niño becomes a more permanent climate fixture

The oceans absorb about 90 percent of the extra heat that is being trapped in the Earth system by greenhouse gases. This could affect the ocean dynamics that control El Niño events.

While there are several theories about what could happen in the future, the most likely consequence of ocean heat uptake is that El Niño, a natural climate phenomenon, could become a more permanent part of our climate system.

That would cause extensive drought conditions in Southeast Asia and elsewhere, while some drought-prone areas such as California would get relief.

The transition is expected to be gradual and take around a century to occur – but it could also be triggered sooner.

Photo: Austin Yoder

 5. The Amazon rain forest dies back

Rainfall in the Amazon is threatened by deforestation, a longer dry season, and rising summer temperatures.

At least half of the Amazon rainforest could turn into savannah and grassland, which – once triggered – could happen over just a few decades. This would make it very difficult for the rainforest to reestablish itself and lead to a considerable loss in biodiversity.

However, the reduction of the Amazon ultimately depends on what happens with El Niño, along with future land-use changes from human activities.

Photo: World Bank

 6. Boreal forests are cut in half

Increased water and heat stress are taking a toll on the large forests in Canada, Russia and other parts of the uppermost Northern Hemisphere. So are forest disease and fires.

This could lead to a 50-percent reduction of the boreal forests, and mean they may never be able to recover. Instead, the forest would gradually transition into open woodlands or grasslands over several decades.

This would have a huge impact on the world’s carbon balance because forests can absorb much more carbon than grasslands do. As the forest diminishes, the climate will be affected as will the Earth’s energy balance.

However, the complex interaction between tree physiology, permafrost and fires makes the situation tricky to understand.

Photo: Gord McKenna

Other concerns…

As if that’s not enough, there are a few other tipping events that scientists are also concerned about, but they are even more complex and harder to predict. Examples of such events include the greening of the Sahara and Sahel, the development of an Arctic ozone hole and a chaotic Indian summer monsoon.

How do we keep from tipping over?

We know from measurements that the Earth has had many climate-related tipping events throughout its history. Today’s situation is different, because humans are now driving these changes and the warming is occurring at a faster rate.

But as humans we also have the power to change the trajectory we’re on – possibly in a matter of a few years. We think we know how.

Also posted in Arctic & Antarctic, Basic Science of Global Warming, Extreme Weather, Greenhouse Gas Emissions, Oceans / Read 1 Response