Current and future storm surge and stormwater flood risk under climate change in Chelsea, Massachusetts
Summary
Floods are some of the most devastating natural disasters and are expected to worsen under climate change due to intensification of extreme precipitation and sea level rise. In this study, present and future flood risk in Chelsea, MA are examined through changes in the 1% annual chance flood event. Future rainfall and storm surge are estimated for two time periods, 2041-2060 (2050) and 2071-2090 (2080) representing the mid and late 21st century, respectively, using a regional climate model and established sea level rise rates for the Boston area.
The output of these simulations show that the historical 1% annual chance rainfall event will be 3x and 3.5x as likely in 2050 and 2080, respectively. The historical 1% annual chance storm surge event will be 3.8x as likely in 2050 and occur at least once a year by 2080.
Using these estimates as inputs into a flood model reveals significant increases in flood risk across Chelsea. The percentage of land area in Chelsea inundated by the historical 1% annual storm surge event will increase from 14% in the present time period to 19% in 2050 and 34% in 2080. While storm surge events cause the greatest flood extents, the 1% annual chance rainfall event impacts the greatest number of buildings in the present time period and 2050. However, the 1% annual chance of joint rainfall and storm surge events impacts the greatest number of buildings in 2080. This finding underscores the need for including pluvial flood modeling in federal flood maps.
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More than 100 countries agree: It’s time to end deforestation
Together they represent more than 85 percent of the world’s forests
Leaders from more than 100 countries pledged to halt deforestation by 2030, as part of an agreement inked Tuesday at COP26, the United Nations climate summit taking place in Glasgow, Scotland.
The U.S., Brazil, and Russia were among the nations that signed the agreement, which is backed by more than $19 billion in public and private funding. Representing more than 85 percent of the world’s forests, the signatories committed to protecting and restoring forests while promoting sustainable land-use and agricultural practices.
Combating deforestation is seen as a crucial step in limiting the impacts of climate change, as the world’s forests absorb roughly one-third of carbon emissions annually. Agriculture, forestry and other land uses account for nearly a quarter of global greenhouse-gas emissions, according to the U.N. Intergovernmental Panel on Climate Change.
Read the full article on Grist.
Protected land status determines a forest’s fate
With a global initiative on deforestation announced in Glasgow Monday, there’s a spotlight shining on places like the Amazon.
Researchers say that land status, such as whether a swath of rainforest is within a protected reserve or recognized indigenous lands, can be the determining factor in deforestation.
Why it matters: Due to land clearing for agriculture or other uses, parts of the Amazon have already passed a tipping point from a net absorber of carbon emissions to a net source, and the pace of deforestation has increased in recent years, threatening the Paris Agreement’s temperature targets.
Read the full article on Axios Generate.
Protect old growth
Of all the tools we have to fight climate change, there’s one we’re destroying instead of deploying—trees.
Restoring and expanding forests is vitally important, but no substitute for preserving the forests we have.
Protect old growth forests now.
Preventing catastrophic climate change will require not only the elimination of fossil fuel emissions, but also pulling significant amounts of carbon back out of the atmosphere. Natural ecosystems, from forests to marshes, currently absorb and hold a quarter of human carbon dioxide emissions, and there is potential for nature to do even more.
But nature, alone, cannot meet the full scope of the challenge. On the other hand, new technologies may not be viable soon enough to make a difference. We bring together diverse expertise to explore the combined potential of natural and technological carbon capture and storage for restoring a stable climate.
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Vapor storms are threatening people and property
More moisture in a warmer atmosphere is fueling intense hurricanes and flooding rains
The summer of 2021 was a glaring example of what disruptive weather will look like in a warming world. In mid-July, storms in western Germany and Belgium dropped up to eight inches of rain in two days. Floodwaters ripped buildings apart and propelled them through village streets. A week later a year’s worth of rain—more than two feet—fell in China’s Henan province in just three days. Hundreds of thousands of people fled rivers that had burst their banks. In the capital city of Zhengzhou, commuters posted videos showing passengers trapped inside flooding subway cars, straining their heads toward the ceiling to reach the last pocket of air above the quickly rising water. In mid-August a sharp kink in the jet stream brought torrential storms to Tennessee that dropped an incredible 17 inches of rain in just 24 hours; catastrophic flooding killed at least 20 people. None of these storm systems were hurricanes or tropical depressions.
Read the full article by Dr. Jen Francis on Scientific American.
Greenhouse gas emissions from burning US-sourced woody biomass in the EU and UK
Summary of research findings
Introduction
As more and more countries adopt climate targets to achieve net zero greenhouse gas emissions, the relevance of forests as stores of sequestered carbon has increased. However, the growing use of forest biomass to generate electricity and heat has raised concerns over the immediate emissions resulting from burning wood.
Many national and intergovernmental policy frameworks, including those of the EU and UK, currently treat biomass energy as zero-carbon at the point of combustion. Accordingly, they grant it access to financial and regulatory support available for other renewable energy sources. These incentives have driven a rapid increase in the consumption of biomass for energy, even though its combustion may increase atmospheric concentrations of carbon dioxide (CO₂) for years or even decades to come.
This report examines the issue in relation to one particular source of woody biomass: wood pellets sourced from the US that are burnt for electricity and combined heat and power (CHP) in the EU and UK. Although wood pellets represent only a proportion of the total woody biomass consumed for energy in the EU–and of forest harvests in the US–the market has grown rapidly in recent years. US-sourced pellets account for the majority of wood pellet imports to the UK and are an important source for the EU.
In 2019, according to our analysis, US-sourced pellets burnt for energy in the UK were responsible for 13 million–16 million tonnes of CO₂ emissions, when taking into account emissions from their combustion and their supply chain, forgone removals of CO₂ from the atmosphere due to the harvest of live trees and emissions from the decay of roots and unused logging residues left in the forest after harvest. Almost none of these emissions are included in the UK’s national greenhouse gas inventory; if they were, this would have added between 22 and 27 percent to the emissions from total UK electricity generation, or 2.8–3.6 percent of total UK greenhouse gas emissions in 2019. This volume is equivalent to the annual greenhouse gas emissions from 6 million to 7 million passenger vehicles.
Emissions from US-sourced biomass burnt in the UK are projected to rise to 17 million–20 million tonnes of CO₂ a year by 2025. This represents 4.4–5.1 percent of the average annual greenhouse gas emissions target in the UK’s fourth carbon budget (which covers the period 2023–27), making it more difficult to hit a target which the government is currently not on track to achieve in any case.
While emissions are likely to fall by 2030, with the end of government support for power stations converted from coal to biomass, they could rise again thereafter if bioenergy with carbon capture and storage (BECCS) plants are developed at scale.
Conclusions and recommendations
The treatment of biomass as zero-carbon in policy frameworks has led governments to provide significant financial and regulatory support for the use of biomass for power and heat. Since emissions take time to be reabsorbed by forest growth, carbon emissions in the atmosphere will increase for a period of decades or even centuries, depending on the feedstock type. Policymakers in consumer countries will be given a false sense of optimism about the progress being made in decarbonizing their energy supply, while producing countries have no corresponding incentive to reduce future emissions in compensation. Subsidies for biomass energy have been delivered–and seem likely to continue–with essentially no mechanism to discriminate between feedstocks with different carbon payback periods, and therefore no effective means of limiting the impact on the climate.
The type of feedstock used in biomass plants is critical. We conclude that only those categories of feedstock with the lowest carbon payback periods should be eligible for financial and regulatory support. This is consistent with the Paris Agreement’s aim of peaking global emissions ‘as soon as possible,’ and reduces the chance of reaching a climate tipping point.
The current sustainability criteria in the EU and UK that define the categories of biomass feedstock that can be supported and the conditions under which they can be burnt do not take account of the real impacts of different feedstocks on the climate and cannot, accordingly, achieve this aim. They are also defective in other ways. (If adopted, the new proposals published by the European Commission in July 2021 would improve EU sustainability criteria somewhat, but their impact would be very limited.) We therefore recommend that EU and UK sustainability criteria be amended as follows:
Only those categories of feedstock with the lowest carbon payback periods should be eligible for support: sawmill and small forest residues and wastes with no other commercial use whose consumption for energy does not inhibit forest ecosystem health and vitality.
- Much tighter definitions of feedstock categories should be introduced to prevent whole trees being treated in the same way as genuine residues.
- Periodic monitoring of feedstock use and impact should be conducted to ensure that allowable feedstocks are not diverted from other uses–e.g. for wood products.
- Additional criteria should be included to protect particular types of landscape, including primary and highly biodiverse forests, from the extraction of biomass for energy. (This is included in the European Commission’s new proposals.)
- The UK’s adoption of a ceiling on feedstock supply chain emissions of 29 kg CO₂eq/MWh is welcome in limiting the types of feedstock that can be used; it seems likely to restrict feedstocks to domestically sourced products. Similar limits should be introduced in the EU.
- The energy efficiency thresholds for new power stations in the EU criteria should be increased and extended to both older and smaller installations.
- The new proposals from the European Commission to extend support beyond 2026 for the use of forest biomass in electricity-only installations in coal-dependent regions will encourage further coal-to-biomass conversions and should be dropped.
- Feedstock for BECCS plants should be subject to at least the same constraints as other biomass plants.
Emissions from any type of biomass used for energy not satisfying the criteria proposed above should be included in full in the consuming country’s greenhouse gas totals when judging progress against their national targets and in relevant policy frameworks, such as the EU’s Emissions Trading System. Since these categories of feedstock have longer carbon payback periods than those eligible for support under our recommendations, this would be an effective way of ensuring that the period during which carbon concentrations in the atmosphere are higher than they would otherwise have been is not simply ignored, as it is under existing policy frameworks.
Beyond 1.5: Tipping points: Is there a point of no return?
Arctic permafrost and tropical forests are two of the most powerful natural drivers of our climate system, and both are approaching the point of tipping from carbon sinks to carbon sources–with potentially catastrophic consequences. At the same time, the ice sheets of Greenland and Antarctica are nearing points of no return, beyond which they may be committed to complete melting that would cause massive sea-level rise. Continuing to emit greenhouse gases without knowing where these tipping points lie is like driving toward a cliff in the fog. This gripping event will explore what we know–and need to know–to avoid going over the cliff.
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