Are carbon offsetting schemes scientifically valid in combating climate change?

Environment | Forests

By Julia Riopelle, Co-Editor in Chief

Published January 15th, 2023

Climate change is a multifaceted issue; a complex combination between environmental, political, economic and social concerns. Whilst we have reached a global consensus that it must be addressed, agreeing on a common course of action has so far proved to be unfruitful.

Despite constant international climate conferences, negotiations and net-zero targets, remaining under the Paris Agreement 1.5°C temperature limit still poses a challenge. This is likely due to the fact that climate change is not a linear matter.

Tree planting in . | @eyoel_kahssay_photographer / Unsplash

Depending on who is speaking on the topic, be it a scientist, a politician or the everyday citizen, as well as who stands to win or lose from certain approaches, will influence which policies on mitigating climate change will be deemed most important.

Whilst most originally viewed climate change as a predominantly scientific concern, those who are already feeling its consequences now would argue that it is also an issue of development, inequality and justice. When discussing solutions to climate change, it is important to consider from what perspective an actor comes from. Most often it is the framing of those in power who determine the direction of negotiations—it is their interests which come out on top.

How to mitigate and adapt to climate change has been the major focus of international debate over the past decades; it is a question of whether to address the root cause of greenhouse gas emissions (GHG) or treat the symptoms through carbon capture technologies and carbon offsetting schemes.

One of the many proposed ‘solutions’ towards the climate crisis are carbon offsetting schemes, which often take form through reforestation and afforestation projects in the Southern hemisphere.

The rationale behind carbon offsetting and reforestation projects

Carbon offsetting allows countries, institutions and companies—usually higher economically developed countries included in the Kyoto Annex I and Annex II categories—to compensate for their domestic GHG emissions by investing in projects that sequester or mitigate equivalent GHG emissions elsewhere—usually lower income countries (LICs).

The first offsetting project took place in 1989, where the American electric power company Applied Energy Services funded an agroforestry project in Guatemala, in order to offset their coal-fired power plant in the US. The concept of carbon offsetting was then linked to the UNFCCC during the 1997 Kyoto Protocol, where it was introduced under the Clean Development Mechanism (CDM).

The rationale behind it is that the flexibility of the CDM offers an economically efficient way to make global carbon cuts, allowing industrialized countries to meet their emissions targets by transferring environmental funding and technological development to LICs. The policy was continuously refined during later conferences, including the EU Emissions Trading Scheme, the Paris Agreement and the UN Carbon Offset Platform.

Carbon offsetting takes two forms: compliance or voluntary offsetting. The primary difference between the two is that compliance offsetting is obligatory for those who signed the agreements set out by the CDM, have a more established regulatory framework and take place at a national level, whereas voluntary offsetting was developed by businesses and NGOs in the 1990s and is primarily motivated by corporate social responsibility.

‘Carbon offsetting allows countries, institutions and companies to compensate for their domestic GHG emissions.’

Projects included within the CDM scheme range from renewable energy, soil management, waste management, gas capture, and afforestation/reforestation. Hence the main arguments for supporting the Clean Development Mechanism are that carbon offsetting cancels out GHG emissions, is cost-effective, allows for a re-allocation of environmental funding and helps LICs to develop in a sustainable way.

Whilst this scheme sounds good in theory, viewing carbon offsetting through various lenses highlights some of its practical drawbacks. The main point to highlight when discussing carbon offsetting as a solution to climate change is that it is an adaptation solution, not a mitigation solution.

Carbon offsetting does not necessarily reduce global GHG emissions—particularly not of those countries that emit the largest amounts of carbon dioxide—it simply provides a means to either recapture it or reduce it elsewhere. Thus, from a scientific perspective carbon offsetting as a means to reach net-zero works on a global level, yet falls-short on a national level.

Questions also start to arise around where these emissions reductions are counted: is it reducing the emissions of the industrialized countries who are funding the project, or are they counted by the LICs in which the projects are based? How often do discrepancies in global emissions targets occur if these reductions are double counted?

Deforestation in Sangre Grande, Trinidad and Tobago. | Renaldo Matamoro / Unsplash

Discourses surrounding the functionality of forests as ‘carbon sinks’ have made afforestation and reforestation projects popular in carbon offsetting schemes. According to the IPCC (2019), 23% of anthropogenic GHG emissions between 2007 to 2016 stemmed from agriculture and other forest-related land-use changes, highlighting just how much carbon storage potential forests have.

In 2020, headlines hit that due to deforestation, the previously dubbed ‘Earth’s lungs’, the Amazon Rainforest, now emits more carbon dioxide than absorbs—a sink often said to store up to 10% of global forest carbon. However, sequestration rates of forests depend on many factors, such as time, place, soil quality and type of fauna—raising concerns for any mismatches between GHG emitters and how much their investments are truly offsetting.

Whilst there are definitely positives to replanting forests aside from just carbon sequestration—such as reducing the impacts of hydrological cycling in watersheds, supporting species diversity, protecting coasts, mitigating soil erosion, biophysical cooling and regional climate regulation—will replanting new forests be able to sequester enough carbon dioxide to balance out current emission rates?

Carbon sequestration researchers have argued that rather than focussing on planting new forests, the conservation of older secondary forests (>20 years) should be the primary focus of climate change mitigation, as well as the preservation of primary forests if we are to meet ‘policy-relevant timescales.’

‘Will replanting new forests be able to sequester enough carbon dioxide to balance out current emission rates?’

Their reasoning stems from that depending on their biomass and age, forests have different above ground carbon storage potentials. The team found that secondary forests in the Amazon take 50 to 100 years to reach the aboveground carbon storage potential of primary forests. Another study found that after 18 years of forest regeneration in Uganda, the biomass of the new forest remains to be only 12% that of old-growth forests.

On top of that, 50 years of afforestation in the UK has still resulted in a net emission of carbon, where new forests have replaced old growth forests and drained peatlands. Therefore, one must question if reforestation/afforestation projects are an effective solution to climate change. Perhaps in 100 years time, but that is time we do not have.

There is also the concern that if carbon sequestered by forests is not measured correctly, or re-emitted through leakage (deforestation moving elsewhere) and permanence (wildfire, disease or pests), then the credits themselves would become false.

The UN also allows plantations and monocultures to be counted as carbon offsetting projects, despite endangering both Indigenous people and biodiversity. Whilst 23,100 hectares of monoculture eucalyptus could offset 13 million tonnes of carbon dioxide, it has been opposed by local Brazilian farmers for ‘threatening local flora and fauna.’

Eucalyptus plantations in Brazil count as carbon offsetting projects, yet endanger Indigenous people and local biodiversity. | Victor Camilo / Flickr

So, from a scientific framing, whilst trees do sequester vast amounts of carbon dioxide and one cannot go wrong planting more trees, there are clear methodological difficulties in quantifying carbon storage, leading to emission discrepancies, as well as concerns surrounding biodiversity due to the inclusion of monocultures.

Featured Image: Arun Clarke | Unsplash

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