General Election: party pledges on tree planting

Tree planting pledges have featured prominently in the General Election campaign – but how do they stack up against what’s actually needed?
By Guy Shrubsole    |      Published:  25 Nov 2019    |      5 minute read

This blog was updated on 28 November to reflect fresh announcements from the Labour party on trees.

Friends of the Earth has crunched the numbers from the party manifestos now published by the Conservatives, Labour, Liberal Democrats and Greens, and compared them to what’s required to meet official climate recommendations – and our own goal of doubling UK tree cover.

A million trees sounds like a lot, doesn’t it? But the world of trees is dominated by huge numbers. Earth has, according to scientists’ best estimates, around 3 trillion trees. The same study states the UK has around 3 billion trees.

It’s staggering figures like these that provide vital context for assessing whether the eye-catching tree planting pledges now being touted around the General Election campaign are as impressive as they seem. Making sense of these pledges is made harder by everyone using different measures: some talk about sheer numbers of trees, others about hectares to be planted, and still others about percentages of woodland cover. So, we’ve run the numbers for you.

First, let’s break down the numbers on what we think is actually needed.

The Committee on Climate Change (CCC) has published two recent reports that discuss the need for many more trees and woodlands – one on land use and the second on its formal recommendations for how to reach net zero carbon emissions by 2050. In the net zero report, the CCC recommends increasing UK woodland cover from its current low level of 13% of total land cover to at least 17%, and – in its "stretch" scenario – 19% of UK land cover by 2050.

Friends of the Earth’s own recommendations are more ambitious. We want to see a doubling of UK tree cover by 2045 (from 13% to 26% of UK land cover). That’s because we believe we need to go further and faster than the CCC say to reduce and draw down carbon emissions: climate breakdown is hitting sooner, the science is more urgent, and climate justice demands we act faster. What’s more, we have the necessary land space available – providing we reduce our consumption of meat and dairy over time – so why wouldn’t we grow more trees on the land we free up? After all, even doubling our woodland cover from today’s low levels would still leave us way behind many other countries: the current EU average woodland cover is 37%.

Green energy suppliers Octopus Energy - tree planting
Credit: Octopus Energy

Breaking down the numbers, here’s what’s needed to meet our goal of doubling UK tree cover by 2045:

  • UK woodland cover is currently 13% of total land area, so doubling it would take us to 26%.
  • The UK currently has 3 million hectares of woodland (made up of roughly 3 billion trees). [1]
  • That works out at an average density of 1000 trees per hectare.[2]
  • Which means that to double UK tree cover we need to add another 3 billion trees, covering an additional 3 million hectares.
  • To reach this over the 25 years between 2020 and 2045, we’d need to add trees at a rate of 120 million trees per year, or 120,000 hectares per year.

(Note that we’re not explicitly calling for only tree planting – we’d just as rather see natural regeneration of trees through rewilding, though planting remains a sensible option where there’s no local seed source.)

Against this, we can see that only one of the UK political parties’ tree-planting pledges – that of the Labour party – matches our level of ambition:

Labour's initial manifesto had pledged “an ambitious programme of tree planting, with both forestry and native woodland species”, but didn't detail a specific figure.

However, the party has also now published a "Plan for Nature" which pledges to plant 300 million trees by 2025, 1 billion by 2030, and 2 billion by 2040.

Breaking this down, that’s a rate of 60 million trees per year from 2020 to 2025, 140 million trees per year between 2025 and 2030, and 100 million trees per year from 2030 until 2040. We’ve assumed a planting density of 1000 trees per hectare, meaning 2 million hectares (ha) of new woodland by 2040.

  • Extending this planting rate to 2045 would result in 2.5 million ha of new woodland, ie 5.5 million ha total UK woodland cover or 22.9% of total UK land area.
  • Maintaining this planting rate until 2050 would result in 3 million ha of new woodland, ie 6 million ha total UK woodland cover or 25% of total UK land area – exceeding the CCC’s recommendations and effectively hitting Friends of the Earth’s ambition of doubling UK woodland cover.

The Conservatives have pledged to plant 30 million trees per year, or 30,000 ha annually, between 2020 and 2025.

  • Extending this planting rate to 2045 would result in 750,000 ha of new woodland, ie 3.75 million ha total UK woodland cover or 15.6% of total UK land area.
  • Maintaining this planting rate until 2050 would result in 900,000 ha of new woodland, ie 3.9 million ha total UK woodland cover, or 16.25% of total UK land area – not actually hitting the CCC’s lower recommendation, and falling well short of our doubling ambition.

The Liberal Democrats have pledged to plant 60 million trees per year, or 40,000 ha annually, between 2020 and 2025. (They appear to have used a higher planting density of 1,500 trees per hectare to arrive at this conversion).

  • Extending this planting rate until 2045 would result in 1 million hectares of new woodland, ie. 4 million ha total UK woodland cover, or 16.7% of total UK land area.
  • Maintaining this planting rate until 2050 would see a total of 1.2 million ha of new woodland, ie 4.2 million ha total UK woodland cover, or 17.5% of total UK land area – hitting the CCC’s lower recommendation, but falling well short of our doubling ambition.

The Greens have pledged to plant 70 million trees per year, or 70,000 ha annually, between 2020 and 2030.

  • Extending this planting rate until 2045 would result in 1.75 million hectares of new woodland, ie. 4.75 million ha total UK woodland cover, or 19.8% of total UK land area.
  • Maintaining this planting rate until 2050 would result in 2.1 million hectares of woodland, leading to 5.1 million ha total UK woodland cover, or 21% of total UK land area – exceeding the CCC’s lower and "stretch" recommendations, but still falling short of our doubling ambition.

And of course, having targets for more trees is only the first step. Parties need to ensure that tree planting delivers the right trees in the right places to maximise biodiversity benefits, and make the supply chain sustainable. They also need the policies and funding to deliver their pledges, and this has featured little in the election (though the Greens have a welcome commitment to agro-forestry, Labour supports greening the Green Belt and using citizens’ assemblies to identify tree-planting sites, and the Lib Dems and Conservatives see agricultural subsidies being redirected to environmental schemes).

This election campaign has seen much greater ambition on trees from all parties – but big numbers are meaningless without context. And, given the climate emergency we face, it’s right that we apply a precise standard.

We think the UK needs to double its tree cover, to draw down millions of tonnes of carbon and make more space for nature. We have the land to do so – what is missing is the political will. While all parties have pledged significant increases in tree cover, only Labour has promised a level of ambition that matches our own. We look forward to seeing more detail on the parties’ policies as the campaign unfolds, and will continue to push every party to do more.

Endnotes:

[1] Crowther, T., Glick, H., Covey, K. et al. Mapping tree density at a global scale. Nature 525, 201–205 (2015) doi:10.1038/nature14967. Crowther’s study produced forest tree density estimates for all countries globally. Supplementary Table 2 states the UK has 3,004,205,568 trees (ie 3bn). See spreadsheet: https://static-content.springer.com/esm/art%3A10.1038%2Fnature14967/MediaObjects/41586_2015_BFnature14967_MOESM90_ESM.xlsx

[2] This 1000 trees per hectare planting density figure is also very similar to the one used by Forest Research in their calculations for average planting density (1150 trees per hectare). See spreadsheet: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/779804/FC_New_Planting_Trees_England_Apr10_Sep18_Constituencies_LAs_Data_Tables.xlsx