Adam Stoner

Adam Stoner

Podcast and audio producer

🎙 Podcast
📬 Newsletter

1,000 trees and 1.5 degrees

Published Friday, 20th November, 2020

The average UK citizen produces 8.45 metric tonnes of CO2 (tCO2e) per year. The average globally is 4.8. In the next ten years – and in order to prevent a 1.5 degrees of global warming – we need to reduce our individual carbon footprints by as much as 65%.

These findings come from a report titled 1.5 Degree Lifestyles which states that worldwide, citizens and societies need to aim for per-person consumption-based greenhouse gas emissions targets of 2.5 tCO2e in 2030, 1.4 by 2040, and 0.7 by 2050 in order to keep global temperature rise to within 1.5 degrees of change.

Used with permission of the Global Carbon Project (2019) under CC-A 4.0 license.
Used with permission of the Global Carbon Project (2019) under CC-A 4.0 license.

The Global Carbon Project (whose graphs are above) estimates we have less than 10 years at current levels of emission before our 1.5º budget is entirely spent. At that point, our ability to correct the see-saw and prevent the threat of climate change tipping points setting in – something which James Lovelock theorises is already happening – is seriously hampered.

As Fiona Harvey writes in the Guardian, scientists are warning that beyond a rise of 2º, the impacts of climate breakdown are likely to become catastrophic and irreversible, yet current global commitments to cut greenhouse gas emissions under the Paris Agreement are estimated to put the world on track for 3º of heating.

From the IPCC's Special Report: Global Warming of 1.5ºC

As the IPCC reflect in their Special Report, cutting our lifestyles to meet these targets isn't going to happen by magic nor is it going to happen overnight. We must alter our lifestyles and we must do it immediately.

Pathways limiting global warming to 1.5°C with no or limited overshoot would require rapid and far-reaching transitions [...] These systems transitions are unprecedented in terms of scale [...] and imply deep emissions reductions in all sectors, a wide portfolio of mitigation options and a significant upscaling of investments in those options – IPCC 'Global Warming of 1.5º'

We must accept these simple facts:

Adapted from Professor Julia Steinberger's '10 Basic Facts for Human and Planetary Survival' diagram.

  1. The climate crisis is really bad.
  2. On our current trajectory it will become much worse.
  3. We can still prevent it from worsening.
  4. This will require rapid, far-reaching changes.
  5. This change is compulsory for human survival.
  6. The systems we operate in are responsible for this crisis.
  7. Maintaining the current trajectory is in the interest of most of these systems. Therefore, we should not expect these systems to change themselves.  
  8. People built these systems. It is people who must change these systems.
  9. Survival depends on us changing these systems.

To quote American architect and futurist Buckminster Fuller:

You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete.

To cut down his carbon footprint in line with the targets that 1.5 Degree Lifestyles espouses, Lloyd Alter of Treehugger is trying to live what he calls a 2.5-tonne lifestyle. Meanwhile, British activist Rosalind Readhead is attempting to live a 1-tonne lifestyle and has been doing so since September 2019 using Professor Mike Berners-Lee's ‘How Bad Are Bananas?: The Carbon Footprint of Everything’ as a guide. Rosalind says her 'rapid, imperfect prototype' aims to 'give life to what net zero carbon means from a personal perspective [and to] add human flesh to an abstract and remote number.'

This is from Carbon Visuals under a CC-A 2.0 license

At its core, the climate crisis is a carbon crisis. There is too much carbon in the air and to fix the crisis we must commit to removing some.

Planting trees to combat emissions is tantamount to carbon offsetting and whilst I respect that carbon offsets alone cannot solve the problem of global warming – and while there have undoubtedly been abuses in the way offsets have been marketed in the past – I do not feel this invalidates their use in relation to emissions which people are unable to reduce directly.

That said, forestation projects are not certified carbon offsets. The carbon emissions they will sequester will happen in the future, with the vast majority of carbon being captured after 40 years. It is plainly obvious we should try and avoid as many emissions as possible today, then seek to offset the rest. I'm calling emissions I cannot avoid 'circumstantial emissions'; they are emissions that are a consequence (of commuting, of living a modern and connected life) rather than a choice (going on jet-set holidays, buying clothes I do not need).

I have calculated my own carbon footprint in a similar way to Rosalind, using Professor Mike Berners-Lee's ‘How Bad Are Bananas?: The Carbon Footprint of Everything’ as a guide, by assuming worse case scenarios. My footprint turns out to be 4 tonnes of CO2e per annum.

Dave Erasmus, modern day woodsman and leader of both an on- and off-grid lifestyle, has crunched the numbers and reveals that a Pinus Sylverstris (Scots Pine), which is classified as a slow growing conifer, will sequester, at conservative estimates, 355kg of CO2e over a 60 year period.

If I've understood his numbers correctly, by year 60 and at its peak, the tree will sequester a kilogram of CO2e once every seven days. This equates to an average of 5kg CO2e per year over a sixty year period. A government forestry report states that trees in Kielder Forest absorb 2kg of CO2 per year on average whilst Madagascan charity Eden Reforestation Projects reckons that a mangrove tree will sequester over 308kg of CO2 from the atmosphere over the growth life of the tree, averaging 12.3kg per tree per annum.

The success of tree planting as a carbon offsetting measure depends on three key factors:

Scientists in Zurich have theorised that covering an area the size of the United States of America could be the most effective climate change solution to date. It would represent a greater than 25% increase in forested area, including more than 200 gigatonnes of additional carbon sequestered at maturity, capturing around two-thirds of carbon emissions released by humans since the Industrial Revolution. That is where this talk of 'planting a trillion trees' that we heard so much of at the World Economic Forum in Davos in 2020 comes from.

Using Dave's calculations and basing all planting on our three tree rules, sequestering my 4 tonnes of CO2e over a 60-year period would require just 12 trees. Assuming I have been emitting 4 tonnes of CO2e per year for my 25 years so far and will continue to so until I reach the UK life expectancy of 80 I would need to plant one thousand trees.

I joined Bristol-based Offset Earth (now known as Ecologi) almost one year ago because I knew that tree planting was one of the ways forward. Buying the 1,038 mangrove trees via Ecologi that I would need to offset a 4-tonne lifestyle for 80 years would cost £123. Remembering that the average UK citizen produces 8.45 tCO2e per year, it would cost £325 to plant the 2,759 trees required.  

According to the World Bank, 1.236 billion people live in so-called 'high income economies'; the current Gross National Income per capita of this set of people is $45,307. Assuming the average person works from 18 to the current UK retirement age, the £325 it would cost to offset their entire lifetime of emissions would equate to £0.56 pence per monthly paycheque. Even if we were to opt with costlier tree planting schemes like One Tree Planted where one tree costs one US dollar, planting 2,759 trees would cost less than a single months salary in a year, a cost that is plainly affordable when spread over a working career.

You may think this is heading the direction of arguing for a so-called flat-rate 'tree tax' and although it clearly has its adventages (and I support the idea of taxes) I do not feel the solution is a tax... So what is?

I've written on multiple occasions about how the best way to affect positive change is to fund it.  

Giving regularly not only helps protect the causes you care about but it also helps charities plan ahead and make long term investments and improvements that change the world and the lives of people on it. – Myself, in 2019

I think the best climate change solution is simply the knowledge that your entire lifetime can be carbon-neutral (and even carbon-negative) for less than you spend on a spur-of-the-moment shopping spree one stuck-at-home Black Friday.


I've been writing this essay on-and-off for the past year. It has sat in various states of completion and with various different conclusions for many of those months. Writing and researching this essay opened my eyes to plainly obvious solutions and answered questions I didn't know I had about climate change.

I leave you with a question of your own to answer: Knowing that tree plantation programs are well within your budget and that the solution to catastrophic climate change is simply to pull carbon from the air, an act trees do by design, is it not a civic and moral duty to plant those trees?