Can tree-planting mitigate climate change?

Tree-planting is often cited as the antidote to CO2 emissions. So is it just a question of planting more trees? Angus Hanton, Co-founder of IF, looks at the realities of this solution

This is both a quantitative and a psychological question. Let’s start by quantifying.

In the UK there is already significant tree-cover. About 13% of the land area overall – it’s nearer to 19% in Scotland and 10% in England – is covered by trees.

Let’s make the assumption that we can plant enough trees to double the tree-cover. Doubling UK tree-cover would require planting another 3 million hectares, which is about 3 billion trees.

Once these get established, the new forests might be expected each year to put on about 10 tonnes of weight per hectare, of which about half will be due to captured carbon. So this removes about 15 million tonnes of carbon dioxide from the atmosphere each year – which is less than a quarter of a tonne for each person in the UK.

Missing by a mile

Let’s compare that with our carbon consumption/production, which is about 5.5 tonnes per person per year (note that this 5.5 tonnes is probably too low as it doesn’t take account of our displaced carbon emissions in e.g. China, which are released as a result of goods made there for UK consumers).

At best, this level of tree-planting will compensate for 1/22 of our consumption, or about 16 days of our annual carbon output. And this outcome depends on whether we strive to double our current tree-coverage at all. Our current targets fall far below this mark.

During the recent election, the Tories pledged to increase tree-coverage by 30 million annually until 2025. If this were to continue until 2030, this would give us 300 million new trees – exactly one tenth of the amount postulated above. Instead of offsetting 16 days of our annual carbon output if they even deliver on their promise, they would only be offsetting approximately 1½ days out of 365 days’ output.

Big spenders

Of course for other countries, such as many poorer African countries, this amount of planting per person would be enough to cancel all their carbon emissions. Countries like Somalia or Rwanda produce less carbon per person in a year that a typical Brit does in a week.

At least the UK has been slowly cutting its emissions and these have almost halved over the last 30 years, whereas in the US – where the average person produces about three times as much – emissions per capita have only dropped by about 20% per person.

Flying in the face or reality

The second aspect of this is psychological. We desperately want to find solutions that we can tell others to do, so that we don’t have to change our own lifestyles.

An example of this is the – as many might see it – totally incredible claim by EasyJet that they will become carbon neutral because they invest in tree-planting and forest protection projects to offset their fuel consumption.

People want to believe that it’s acceptable to keep jetting around the planet and that they can somehow make it okay – spending a couple of weeks in Australia for sightseeing while lamenting the terrible bush fires.

The reality is that offsetting our carbon output is not enough. Polluting activities, such as flying, will have to be curtailed sharply if we are to do our duty by future generations.

And for the changes we need to make, it won’t be enough to rely on conscience and voluntary change: restrictions and higher taxes on polluting activities will be needed.

Even getting more trees planted will require generous grants or compulsory land purchase – or both.

Credit surplus

Another interesting aspect of tree-planting which is readily observable is that any tree planted is counted by everyone towards their target: credit is claimed by the person who sponsors the cost, the company which actually does the planting, the landowner, the local authority, central government, and the Forestry Commission and others.

They all claim credit. So there is a serious risk of over-counting the amount of tree-planting that actually takes place – another aspect of the observation that “success has many fathers but failure is an orphan.”

Help us to be able to do more

Now that you’ve reached the end of the article, we want to thank you for being interested in IF’s work standing up for younger and future generations. We’re really proud of what we’ve achieved so far. And with your help we can do much more, so please consider helping to make IF more sustainable. You can do so by following this link: Donate