Oxfam warns that governments and businesses who want to plant trees or restore forests to achieve net-zero emission must limit their efforts in order not to drive up food prices in developing countries.Although planting trees is a key way to address the climate crisis has been suggested, the amount of land required for this would be huge. Furthermore, the report Tightening The Net: Net Zero Climate Targets implications for land equity and food equity states that even just a fraction of the area required to offset global greenhouse gas emission would require a lot of land.A minimum of 1.6 billion hectares, an area five times as large as India, would be needed to achieve net zero by 2050 through tree-planting. Although no one suggests planting trees in this extent, the report authors stated that it provided an indication of the required planting and the amount of offset needed if food prices rises.Nafkote Daabi, Oxfam's climate policy leader and co-author, said: It is hard to estimate how much land will be needed, since governments have not been transparent with how they intend to meet their net zero commitments. Many countries and companies talk about afforestation. The first question is where this land will come from.According to some estimates, food prices could rise by as much as 80% by 2050 if forestry is not used enough to offset emissions. An area of 350m hectares, roughly equal to India's size, could be used to offset the effects of climate change without affecting agriculture in the rest of the world. However, the combined plans of offsetting from companies and countries around the globe could quickly exceed this.Dabi stated: Already, hundreds and millions of people are hungry around the globe. It is important to consult other countries about how they will use their land. Companies and countries need to reduce their emissions before relying on offsets. We must also reduce the emissions from agriculture which is the second largest source of global emissions.Reforestation and planting new forests were also two of the most common offsetting measures. Nature-based solutions, which focus on forest management, agroforestry, the practice of growing trees and crop cultivation with pasture management, were found to be far more effective, the analysis revealed. These solutions would allow people to harvest the land and sequester carbon.Dabi said: We don't oppose afforestation or reforestation. And we don't want to stop people from doing these things. They should not be used on a large scale, and should be used in conjunction with other methods like agroforestry.She used the example of Switzerland to illustrate her point. It plans to offset 12.5% of its carbon emissions by purchasing carbon credits from projects in countries like Peru and Ghana. According to Oxfam, this target would require an area approximately the same size as Costa Rica.As part of their efforts towards zero emissions, some companies also plan to use carbon offsets based on trees and land. Oxfam discovered that many of these plans could lead to over-use of land.Four major energy companies, for example, would need an area that is twice as large as the UK to offset their emissions. According to Oxfams estimates Shell would require 28.6m ha by 2050. TotalEnergies, which plans to offset approximately 7% of its carbon emissions, will need around 2.6m ha by 2050. Another energy company Eni plans to plant 8 million hectares of forest, but Oxfam estimates that twice this amount could be required. Oxfam estimates that BP will need as many as 22.5 million hectares to offset as much of its emissions. However, BP has not yet provided details.Chief executive of Oxfam GB Danny Sriskandarajah called on governments and companies to reduce their carbon emissions significantly rather than relying upon offsets. He stated that too many governments and companies are continuing to do dirty business as usual by hiding behind net zero. The oil and gas industry is trying to justify the continued extraction of fossil fuels with unrealistic carbon removal schemes, which require huge amounts of land. This is a prime example of doublethink.He said that net-zero targets were essential to combat climate change. While some companies and governments are making bold steps to reduce emissions, there is not enough to ensure that we are able to avoid climate disaster and the devastation and widespread hunger that it brings.A spokesperson for BP stated that BP did not plan to rely upon offsets in order to achieve its 2030 aims or our 2025 emission reduction targets. They may be able to help us achieve our 2030 aims, however. We support the use by companies, governments and societies of carbon credits or offsets to help them achieve net-zero faster and at lower costs. This will allow them to meet the Paris goals.Shell denied that it had received Oxfam's estimates. A spokesperson for Shell stated that to achieve a net zero target, Shell must fundamentally change the energy sources Shell uses and then use offsets at the margin in order to compensate for any remaining carbon emissions.Shell is shifting its portfolio towards more renewable and lower-carbon energy sources. It could be that the amount of greenhouse gas emissions associated with Shell's energy sales in 2050 will be less than the carbon credits we anticipate being able to provide our customers in 2030.