Corporate carbon polluters plant trees to counter their CO2 emissions, but activists warn against greenwashing and say such afforestation schemes detract from the emissions reductions needed to combat climate change. Voluntary carbon offsetting are being hotly debated at the COP26 climate summit in Glasgow. Here’s a backgrounder. Carbon offsetting is when a company seeks to compensate for its greenhouse gas emissions by investing in a project that reduces emissions somewhere else, whether next door or on the other side of the planet. Such schemes have been around since the 1980s, and include investing in renewable energy, natural carbon sinks such as mangroves, or planting trees that absorb and store CO2 as they grow.
More recently, carbon polluters can even pay companies that suck planet-warming carbon dioxide straight from the air and store it in the ground or transform it into fuel pellets, though the cost per tonne of CO2 removed remains very high. In exchange for reducing emissions, investors earn carbon credits. Firms can be obliged to do this under mandatory initiatives such as the European Union’s Emissions Trading Scheme, or can earn carbon credits on in voluntary markets.