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Environment

Aug 08, 2019

George Monbiot: How rejuvenating nature could help fight climate change.

A PhD Researcher in Climate Change Adaptation discusses how this approach could address the ecological crisis with Guardian columnist and environmental campaigner George Monbiot.

WRITTEN BY

Stephen Woroniecki

Natural climate solutions let nature do the hard work in the fight against climate change by restoring habitats such as forests and wetlands. This could absorb carbon dioxide from the atmosphere and help biodiversity thrive. 

Q: What has inspired you about natural solutions to climate change and what are their chief advantages over other approaches?

They bring together our two crucial tasks: preventing climate breakdown and preventing ecological breakdown. They are all things we should be doing anyway, to limit the scale of the sixth great extinction and protect and restore threatened ecosystems.

In these fields, as in all others, we have often tended to act in isolation, replicating effort, failing to recognise the synergies. Natural climate solutions show how we can use the self-regulating power of the living world to help fend off climate catastrophe.

I should emphasise that even if we use natural climate solutions to the max, we still need to halt almost all greenhouse gas emissions and leave fossil fuels in the ground, if we are to prevent more than 1.5℃ (or even 2℃) of global heating. But it’s now clear that mitigation alone is not enough: we need to draw down carbon that we have already emitted from the atmosphere.

The other main strategies for carbon drawdown are both, in my view, disastrous. The first is bioenergy with carbon capture and storage (BECCS). This means growing biomass in plantations, burning it in power stations to produce electricity, capturing carbon dioxide from the exhaust gases and burying it in geological formations.

Any deployment of BECCS sufficient to cause significant carbon abatement will also cause either humanitarian or ecological disaster, because of the vast amount of land – cropland or wildland – the plantations will replace. It is also likely to be self-defeating, due to the massive carbon pulse that conversion of forest lands to plantations will cause, and the vast amount of extra nitrogen fertiliser required, with its associated greenhouse gas emissions.

The second is direct air capture. Not only is this likely to be extremely expensive, but the carbon-heavy infrastructure it requires, reliant on a huge deployment of steel and concrete, could help push us past crucial climate tipping points before its positive impacts were felt.

These are both bad ways of addressing the problem. Why deploy them when there’s a much better one?

Author and activist George Monbiot. John Russell1/Wikipedia, CC BY-SA

Q: Clearly this is an emerging field, and research is needed to understand how best to implement natural climate solutions. What are some of the boldest and most exciting examples that have already been tried across the world that we can learn from and be inspired by?

At the moment, the two biggest identified carbon sinks are forests and peatlands, but one of the things that excite me most about this field is how little we yet know. Every year, major new possibilities are identified, in ecosystems that hadn’t been fully considered before. For example, we now know that vegetated coastal habitats – such as mangroves, saltmarsh and seagrass beds – can accumulate carbon 40 times as quickly per hectare as tropical forests can, because of the way they catch and bury organic sediments in waterlogged conditions.

Coastal habitats like mangrove forests can store significantly more carbon than inland habitats.
Damsea/Shutterstock

One issue that has scarcely been explored at all is the carbon storage impact of stopping trawling and dredging. The seabed is a vast carbon store, but these activities, that scour over three quarters of shelf seas every year, kick carbon into the water column, where it can be oxidised and released. We don’t yet know for sure, as so little research has been done, but it could be that severely curtailing these destructive activities, which we should do anyway, as they are by far the greatest cause of ecological damage to marine habitats, could result in massively greater carbon storage.

I should mention two key principles. First, this isn’t just about creating new or renewed ecosystems. We also need to protect the Earth’s existing carbon repositories – such as old-growth forests – whose sequestration capacity would take centuries to reproduce. Second, that fertile cropland should not be used. Mass rewilding of the kind I propose should take place only on less productive land. Unlike BECCS plantations, natural ecosystems can thrive on infertile land, without extra fertilisation.

Q: The proposal for a Green New Deal in the US has called for a green transition of society and the economy through investment in renewable energy and by phasing out fossil fuels. How do you see the role of natural climate solutions within a broader transformation of our society and the world we live in?

I think natural climate solutions now need to be urgently deployed by all governments, alongside an extremely rapid reduction in energy consumption and substitution of fossil fuels. To avoid full-spectrum climate breakdown, we need a global cooperative effort on a scale that has not yet materialised. My hope is that the new, uncompromising mood among young people, and the brilliant protest movements, such as the Youth Strike4Climate and Extinction Rebellion, will help to make this happen.

Q: Geoengineering proposals are often criticised for taking risks with natural systems that could have catastrophic consequences, often with little to no consultation from the people who could be most affected. How do we ensure natural solutions are carried out democratically and without echoing the technocratic arguments of many geoengineering projects?

Whatever we do has to be done with and through the people, it might affect, under the “nothing about us without us” principle. Natural climate solutions must work with the free, prior and informed consent of indigenous people and other local communities, and their benefits must flow to these communities. No project should be pursued that undermines their land rights, economic security and well-being. On the contrary, all projects should seek to strengthen them. There are some excellent examples of how this can be done around the world, compiled by the Equator Initiative.

Q: Restoring natural habitats can sometimes mean giving authority to external experts at the expense of local people. What do you think is important to bear in mind when making the case for natural solutions to local communities?

A rain-fed home garden in Sri Lanka which grows food for people and offers refuge for nature.
Stephen Woroniecki, Author provided

I believe all projects should be guided by the Freirean approach – developed by the Brazilian philosopher Paolo Freire – of mutual education and understanding. An outsider should not turn up with the attitude that she has come to impart her superior knowledge to local people. She starts by asking them to teach her about themselves, their lives and needs, and to exchange knowledge, in the hope that all become both educators and educated. The outsider might bring new ideas and perspectives – that are, I believe, essential – while local people bring intimate insights into and knowledge of the peculiarities of place and community, that are also essential.

Q: How can people get involved in designing, implementing and managing natural solutions to climate change?

We list on our website the organisations already involved in the field, some of whom would welcome your help. But the most important thing right now is to spread the word as far as you can.

Click here to subscribe to our climate action newsletter. Climate change is inevitable. Our response to it isn’t.The Conversation

Stephen Woroniecki, PhD Researcher in Sustainability and Climate Change Adaptation, Lund University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Cover photo: Mangrove forest in Kannur, Kerala by Shagil Kannur

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Environment

Aug 20, 2019

Antarctica’s largest floating ice shelf is highly sensitive to warming of the ocean

Much of West Antarctica’s ice lies below sea level, and warming ocean temperatures may lead to runaway ice sheet retreat.

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WRITTEN BY

Dan Lowry

Scientists have long been concerned about the potential collapse of the West Antarctic Ice Sheet and its contribution to global sea-level rise. Much of West Antarctica’s ice lies below sea level, and warming ocean temperatures may lead to runaway ice sheet retreat.

This process, called marine ice sheet instability, has already been observed along with parts of the Amundsen Sea region, where warming of the ocean has led to melting underneath the floating ice shelves that fringe the continent. As these ice shelves thin, the ice grounded on land flows more rapidly into the ocean and raises the sea level.

Although the Amundsen Sea region has shown the most rapid changes to date, more ice actually drains from West Antarctica via the Ross Ice Shelf than any other area. How this ice sheet responds to climate change in the Ross Sea region is, therefore, a key factor in Antarctica’s contribution to global sea-level rise in the future.

Periods of past ice sheet retreat can give us insights into how sensitive the Ross Sea region is to changes in ocean and air temperatures. Our research, published today, argues that ocean warming was a key driver of glacial retreat since the last ice age in the Ross Sea. This suggests that the Ross Ice Shelf is highly sensitive to changes in the ocean.

History of the Ross Sea

Since the last ice age, the ice sheet retreated more than 1,000km in the Ross Sea region – more than any other region on the continent. But there is little consensus among the scientific community about how much climate and the ocean have contributed to this retreat.

Much of what we know about the past ice sheet retreat in the Ross Sea comes from rock samples found in the Transantarctic Mountains. Dating techniques allow scientists to determine when these rocks were exposed to the surface as the ice around them retreated. These rock samples, which were collected far from where the initial ice retreat took place, have generally led to interpretations in which the ice sheet retreat happened much later than, and independently of, the rise in air and ocean temperatures following the last ice age.

But radiocarbon ages from sediments in the Ross Sea suggest an earlier retreat, more in line with when climate began to warm from the last ice age.

An iceberg floating in the Ross Sea – an area that is sensitive to warming in the ocean.
Rich Jones, CC BY-ND

Using models to understand the past

To investigate how sensitive this region was to past changes, we developed a regional model of the Antarctic ice sheet. The model works by simulating the physics of the ice sheet and its response to changes in ocean and air temperatures. The simulations are then compared to geological records to check accuracy.

Our main findings are that warming of the ocean and atmosphere were the main causes of the major glacial retreat that took place in the Ross Sea region since the last ice age. But the dominance of these two controls in influencing the ice sheet evolved through time. Although air temperatures influenced the timing of the initial ice sheet retreat, ocean warming became the main driver due to melting of the Ross Ice Shelf from below, similar to what is currently observed in the Amundsen Sea.

The model also identifies key areas of uncertainty of past ice sheet behaviour. Obtaining sediment and rock samples and oceanographic data would help to improve modelling capabilities. The Siple Coast region of the Ross Ice Shelf is especially sensitive to changes in melt rates at the base of the ice shelf, and is therefore a critical region to sample.

Implications for the future

Understanding processes that were important in the past allows us to improve and validate our model, which in turn gives us confidence in our future projections. Through its history, the ice sheet in the Ross Sea has been sensitive to changes in ocean and air temperatures. Currently, ocean warming underneath the Ross Ice Shelf is the main concern, given its potential to cause melting from below.

Challenges remain in determining exactly how ocean temperatures will change underneath the Ross Ice Shelf in the coming decades. This will depend on changes to patterns of ocean circulation, with complex interactions and feedback between sea ice, surface winds and melt water from the ice sheet.

Given the sensitivity of ice shelves to ocean warming, we need an integrated modelling approach that can accurately reproduce both the ocean circulation and dynamics of the ice sheet. But the computational cost is high.

Ultimately, these integrated projections of the Southern Ocean and Antarctic ice sheet will help policymakers and communities to develop meaningful adaptation strategies for cities and coastal infrastructure exposed to the risk of rising seas.The Conversation

Dan Lowry, PhD candidate, Victoria University of Wellington

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Cover photo: Since the last ice age, the ice sheet retreated over a thousand kilometres in the Ross Sea region, more than any other region on the continent.
Rich Jones, CC BY-ND

 

Introducing The Outdoor Voyage

Whilst you’re here, given you believe in our mission, we would love to introduce you to The Outdoor Voyage – our booking platform and an online marketplace which only lists good operators, who care for sustainability, the environment and immersive, authentic experiences. All listed prices are agreed directly with the operator, and we promise that 86% of any money spent ends up supporting the local community that you’re visiting. Click the image below to find out more.

 

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