Climate change: With atmospheric CO2 up almost 20% in 26 years, we need science to reach net-zero – Professor Mathew Williams

I grew up near botanic gardens and spent much of my childhood climbing exotic trees and hiding among the tropical fronds in Victorian hothouses.

As a teenager, the African droughts and famines of the 1970s and 1980s showed me societies unprepared for and under threat from climate extremes.

It seemed to me then, and it still does, that a rational, scientific approach to our relationship with nature could help solve such problems. These ideas led me to a degree in biology, a doctorate in environmental sciences, and a research career that has taken me around the world. I have been privileged to visit and research a huge diversity of ecosystems, from the Alaskan tundras to the Amazonian rainforests.

I have learned about the extraordinary connectedness in our biosphere between life and landscapes, plants and soils, land and atmosphere, water and energy. I have also witnessed and recorded huge changes in our environment over my research career.

Our atmosphere today has nearly 20 per cent more carbon dioxide than in 1996 when I made my first measurement in Alaska. Brazilian rainforests I studied in 1998 have now been cleared.

When I began my career, ecologists specifically went to study pristine ecosystems, to learn about natural processes away from human pressure. Such an idea seems bizarre now. Ecologists today put human pressures at the heart of much of their research.

So, since coming to Edinburgh in 2000 I have included in my research human-dominated ecosystems in Scotland – farms and forests.

My job as chief scientific adviser is to ensure that all environmental science used within Scottish Government is high quality, particularly about the role of nature in climate change and the future of farming and land use, and coordinates Scotland’s world-class research centres in environment, natural resources and agriculture to ensure their science is taken up and used by society.

The drive to net-zero carbon emissions will be helped by planting trees and restoring peatland (Picture: Christopher Furlong/Getty Images)

There are vital decisions to be made in the next few years about the future of Scottish agriculture post-Brexit. The combined climate change and nature emergencies are at the heart of government. These topics have strong scientific perspectives. So, I have a chance to support the development of effective policies to meet key environmental challenges of our time, mapping a route towards a desirable social and environmental future that is fair and viable.

We know that our climate is changing, driven by our use of fossil fuels. Forest clearance and intense management of our lands and seas are increasing globally. We have to lighten humanity’s footprint on our planet so nature can continue to deliver us the services we take for granted: clean air, fresh water, fertile soils, food, natural fibre, wood, our iconic landscapes, beaches and forests to escape to. I want to be sure that Scotland sits within an environmental ‘safe operating space’, where our lives and economy can thrive.

On Scotland’s dashboard for safe operations, there are already warning lights for biodiversity loss, for air, soil and water pollution and for land system change. Some of these lights have been flashing for decades but the warnings are now more urgent.

Science has shown that profound global changes are underway and further changes are coming. The COP26 summit in Glasgow last year highlighted the challenges we face to avoid dangerous climate change. The global biodiversity conference in China this year, COP15, will highlight the linked nature and climate crisis. Poor land management, driven by human consumption, is destroying the habitat diversity that species require.

But there are solutions. Currently many of Scotland’s extensive peatlands are degraded and emit carbon which warms the climate. But, with efforts such as rewetting, there is a potential to stop peatlands emitting. Science helps us monitor biodiversity, determine its requirements and then evaluate whether our interventions work.

In Scotland, science has helped in conserving red squirrels and reintroducing sea eagles. But there are still outstanding questions and challenges for science that I want to help resolve.

Which trees should be planted and where, to optimise carbon stores and biodiversity? How can we track peat restoration to be sure it stores carbon for decades and enhances biodiversity? How will climate change effect Scottish agriculture, and what opportunities and threats will arise? How can we change our patterns of consumption to be more sustainable?

Research shows peat restoration and increased forest planting are critical for reducing emissions and building natural sinks for carbon, and that rapid progress is required or even greater changes will be necessary in the future.

Forest planting is proceeding on track with targets, including the proportion of native species, although the intense storms of the winter will create pressures on the industry. Peatland restoration has been more difficult because this is a new industry that needs support to grow. Science can help in identifying best approaches and also the key areas to focus restoration on.

There are great opportunities to attract and train people into environmental jobs across Scotland, to be part of the solution.

Covid taught us how important it is to have real-time scientific data on the state of infections, vaccinations and variants. Likewise in tackling our environmental crises we need to focus now on setting up systems to provide data on the state of Scotland’s soils, water bodies, atmosphere, peatlands, trees and biodiversity. This information will help policymakers and society to see the success or otherwise of the actions we take, and to make effective adjustments to our plans.

We also need to use science, allied with economic and social studies, to scope out various scenarios for what a net-zero Scotland looks like in 2045, in terms of wealth and well-being. Trade-offs are inevitable, but can be made justly once society chooses the scenario it prefers. By understanding how we are going to live in Scotland we can generate the momentum towards the changes required for a positive future for all.

Professor Mathew Williams is the Scottish Government’s chief scientific adviser for environment, natural resources and agriculture

A message from the Editor:

Thank you for reading this article. We're more reliant on your support than ever as the shift in consumer habits brought about by coronavirus impacts our advertisers.

If you haven't already, please consider supporting our trusted, fact-checked journalism by taking out a digital subscription.