Companies and governments are adopting the concept in increasing numbers net-zero greenhouse gas emissions targets. These targets often invoke nature as a way of storing or removing carbon from the atmosphere to counter other emissions.
For example, Justin Trudeau, Prime Minister of Canada, promised Greta Thunberg in 2019 that Canada would Plant two billion trees by 2030Investing in nature is now a smart investment. key part of Canada’s climate strategy.
For carbon storage, forests, peatbogs, wetlands, and other ecosystems use photosynthesis to remove it from the atmosphere and store it in their leaves, trunks, roots, and soil. However, carbon storage in nature can be short-term as it is easily lost. Natural disturbances or human activity..
The climate effect of carbon dioxide emissions due to burning fossil fuels is, however, quite different. Effectively, permanent. Are these efforts to increase carbon stocks sustainable?
Our new researchIt is possible to use temporary, nature-based carbon storage to help us achieve our climate goals. However, the most tangible effect — a decrease in peak warming — would only occur if we also eliminate fossil fuel emissions.
Climate solutions that are based on nature
Climate solutions that are based on natureThese are actions that reduce carbon dioxide in the atmosphere by increasing carbon storage within natural systems. Reforestation, nature conservation, and improved agricultural practices are just a few examples. They can help to mitigate climate change by reducing emissions from human land-use or by maintaining and improving natural processes that remove carbon dioxide from the atmosphere.
However, the carbon found in nature is still available. It is unlikely that the atmosphere can be permanently removed. Wildfires and other disturbances would result in carbon being lost to the atmosphere. Also, conflicts in human land-use priorities could cause natural areas that were previously protected to be lost. Industrial activities are threatening.
Nature-based carbon storage would only be of temporary benefit to the climate. To fully appreciate the benefits of nature-based climate solutions, we must consider them in relation to other climate mitigation efforts.
What if the carbon storage that is nature-based is temporary?
Carbon dioxide emissions from fossil-fuels have climate impacts For centuries, they will be there. Nature-based carbon reduction will have a climate effect only as long as the carbon remains in storage.
Our study explored what temporary removal might mean for the future climate. We used a climate modeling tool to simulate the climate’s response to temporary removal.
Global temperatures will rise if emissions continue to rise until 2040 and then slowly decline. Nature-based carbon reduction would only delay the occurrence at a specific temperature. In the most extreme scenario, sequestering 25% annually of current emissions until 2050 does not delay the time it takes to reach 1.5 C, or 2 C, but it does delay 8 years.
However, if future emission levels are reduced quickly to net-zero by the middle of the century and then remain net-negative then global temperatures will peak at 1.6 C. and then drop during the second part of the century. Temporary, nature-based carbon reduction could decrease the temperature peak to as little as one tenth of an inch.
Although this may seem small, it is a tangible and important climate benefit that will only be realized if the world succeeds in eliminating carbon dioxide from fossil fuels over the coming decades.
What should we think of nature-based climate solutions for the future?
Our findings challenge the way that nature-based climate solutions are viewed as a climate policy option. Nature-based climate solutions are often presented in this way: One of many ways that we can reduce our climate impact, and can be used interchangeably with other climate actions. Alternately, there are nature-based solutions These can be used as offsetsSpecifically, not to be used in lieu of other emission reductions.
Both of these framings pose problems. If nature-based carbon stockpiles are temporary, then their climate effect is not equivalent with avoiding fossil fuel carbon dioxide emissions. Nature-based carbon storage should not be considered as an alternative to other emissions cuts. It will, at best delay crossing temperature thresholds. At worst, this could cause more emissions and long term warming.
On the other side, if we take action not only to reduce emissions but also to increase natural carbon stockp, it could help limit peak warming. Even temporary carbon storage from nature could have a positive impact on climate.
The case for improved nature conservation and stewardship
Our results show some of the risks associated with relying on nature-based solutions for climate mitigation at the expense other climate mitigation efforts. Nature conservation and better management of natural areas can be a way to mitigate climate change. Other positive environmental outcomes. These environmental cobenefits, like increased biodiversity and better water and air quality are also crucial to climate resilience.
Nature-based solutions can also be achieved if they are implemented in partnership with Indigenous communities and other local communities. positive social co-benefitsSuch as supporting livelihoods or cultural values. These multiple benefits can be realized by taking a holistic approach to nature-based climate solutions.
Nature-based climate solutions should not be considered as an alternative to other options for climate mitigation. They could be a complement to other climate mitigation options, and play an important role in meeting other sustainability goals.