I wrote the first part of this post on the 50th anniversary of the first human stepping onto the moon. An impressive feat of science and engineering then, given the limitations of available technology, and seeing and hearing the coverage using original material from the archives make it seem no less impressive today. The prodigious consumption of fuel required to lift the Saturn V rocket towards escape velocity and earth orbit was one of the less palatable characteristics of the Apollo programme. One of the more surprising features of footage of the launch, given the need for fuel efficiency, is the dark exhaust trail left behind by the rocket. The fuel for the first stage was similar in make-up to kerosene, used in contemporary airliners, and produced the same exhaust products. A by-product of the commercial success of budget airline Ryanair is that it is now one of the ten most polluting businesses in Europe, all of the others being coal-powered energy generators. It serves as an illustration of how the important issues can sometimes be missed, that some of the messaging at either end of an air flight (which in this instance was with Ryanair) focuses on small things and misses the elephant in the room. Washroom hand dryers at the UK end and electric airport vehicles at the other may well be lower carbon than alternative technologies, but the connecting flight dwarfs the significance of both. All sectors of the economy need to do their bit, but airports aren’t much use without airlines and vice versa, so the entire system should really be taken into account as a connected whole if the true impact is to be considered and mitigated.

Planting trees, in person or through offset schemes, as many air passengers – including me – do in order to offset their emissions only takes you so far, of course, but large-scale afforestation is one of the recommendations in the Committee on Climate Change (CCC)’s recent report which led to the Westminster government’s adoption of a net-zero carbon target for the UK by 2050 and the devolved administrations in Scotland and Wales taking comparable action. Tackling emissions from land use and land use change makes for a large part of the extra 20% reduction beyond the original ambitions of the 2007 Climate Change Act, and the scale of proposed tree planting is significant. At the top end the CCC’s figures would result in an increase of UK woodland of close to 50%, largely using land released by a recommended move away from ruminant agriculture. The economic change required within the agri-food sector to deliver this would be significant and would need to be replicated globally for climate change mitigation to have any hope of success. We think of deforestation as a modern phenomenon but the Domesday Book records levels of forest cover only a little higher than now (albeit the geographic range excluded Scotland which today has the most woodland of the countries of the UK). That said, by the beginning of the 20th Century woodland cover was below 5% and the increase to today’s level of 13% is in large part the consequence of government action in response.

That figure of 13% still compares badly with the rest of Europe and most other regions of the world, and an increase to 19% in line with the CCC report would only reach the levels of tree cover in Asia. In densely populated countries it is obviously harder to find space for nature than in areas where human impact has been lower. Sub-Saharan population growth is projected to add another billion to the global population which will put significant strain on woodland cover which is already only at 21%. It is heartening to see the Green Legacy initiative in Ethiopia which on 29th July this year led to the planting of over 350 million trees in 12 hours with an eventual target of 4 billion and at only 4% tree cover, down from 35% a century ago, Ethiopia has much woodland and forest to recover. Critics of the government claim the project is a stunt to divert attention from other problems in the country. Whether or not those claims are valid, the woodland benefit in potentially mitigating climate impacts in the region – plus other health benefits associated with natural landscapes – remains real.