Climate change and how to combat it

With so many of us rediscovering the immediate benefits of gardening during the coronavirus lockdown, it’s easy to overlook the long-term crisis of climate change. But there are simple steps we can all take now in our gardens that will make a big differen

In the search for a glimmer of normality and a sense of hope for the future, it isn’t surprising that the nation has turned to gardening when faced with the coronavirus lockdown. And the weekly applause emanating from our doorsteps suggests we’ve become acutely aware of the need for the caring and nurturing skills being shown in our hospitals and schools.

But the current crisis isn’t the only global challenge we face. In the Government’s spring Budget, as well as the initial financial provision to deal with Covid-19, funding was announced for initiatives to combat climate change, the biggest threat to humanity and life on our planet.

The UK has also passed legislation to reduce greenhouse gas emissions to net zero by 2050 and to prepare for the impacts of climate change, in response to findings set out in the Committee on Climate Change’s Net Zero report (May 2019) and Reducing UK Emissions progress report (July 2019).

Such news has understandably been knocked off pole position in the light of daily updates and health advice concerning Covid-19, but at the same time there are some sobering and graphic climate-related outcomes resulting from the lockdowns and restrictions on travel.

Most notable is the massive reduction in particulate and greenhouse gas emissions from our transport infrastructure and manufacturing, as our journeys and lifestyles have been restricted. Meanwhile in China emissions of carbon dioxide (CO2) fell by a quarter during lockdown, although levels have risen quickly as its economy returns to normal.

There will be more monitoring and analysis over the weeks and months to come, and it will undoubtedly reveal more about the scale of what needs to be done in order to mitigate climate change. It will also provide an insight into how we need to adapt our habits and day-to-day lives.

Even if we cut all emissions around the world tomorrow, the amount of greenhouse

gases that have accumulated in the atmosphere will mean a continued rise in global temperatures long into the future. And as a result of previous emissions, we’ve already seen changes to overall climate and weather patterns around the world, as well as here in the UK. All ten of the UK’s warmest years on record, for example, have been since 2002, according to the Met Office.

Weather warning

But it’s not just overall atmospheric temperatures that are increasing. A warming world means there’s more energy to drive the climate systems, giving rise to extreme events such as droughts, floods and hurricanes as weather patterns change (see panel on p67).

So far in the UK, the most recent decade (2008-17) has been on average 0.8°C warmer than the 1961-90 average. That might not sound much, but for UK gardeners and growers this has been enough to extend the length of our growing season, delay the onset of the first frosts and cause plants to flower earlier in spring.

As for the changes to come, predictions vary widely depending on the world’s ability to control its greenhouse gas emissions. But modelling from the Met Office Hadley Centre predicts that by the end of the century, UK average winter temperatures may be as much as 4.2°C higher and summer temperatures up to 5.4°C higher than the 1961-80 average.

In addition, we are likely to see higher rainfall in winter and lower levels in summer, coupled with an increase in the current regional differences from west to east across the UK. The predictions also suggest a 25 per cent increase in intense and long-lasting rainfall events. Meanwhile, frost and snow will continue to become less prevalent, although they can’t be ruled out.

It’s not hard to see what such changes will mean to gardeners and their growing ambitions – whether it be a windowbox, balcony, urban patio or rolling rural acres. And while the changes may seem gradual, the need to urgently cut our greenhouse gas emissions and prepare for the climate changes to come has never been greater.

What can we do?

The Royal Horticultural Society’s Garden Matters: urban gardens is a useful guide to how our gardens can help to moderate temperatures, combat flooding, support biodiversity and maintain human health. Meanwhile Gardening in a Changing Climate looks at UK climate change and weather projections, and how they will affect our gardens. Both are available free at rhs.org.uk.

Meanwhile, understanding how soils and plants work, increasing your plant knowledge, developing an appreciation of the microclimate and prevailing conditions in your local area, as well as honing your gardening and growing skills, will all help you cope with the challenges to come. Observing and adapting is, after all, what we gardeners do!

A warming world means there’s more energy to drive the climate systems, giving rise to extreme events such as droughts, floods and hurricanes