How would planting 8 billion trees every year for 25 years affect Earth’s climate?

Planting 8 billion trees every year for 25 years would be an ambitious and commendable effort to combat climate change. The primary benefit of planting trees is that they absorb and store carbon dioxide from the atmosphere, which helps to slow the warming of the planet. 

According to the United Nations, the human population of Earth reached 8 billion in Nov 2022. The burning of fossil fuels, deforestation, and other human activities lead to the emission of over 36 billion tonnes of carbon dioxide into the atmosphere each year. While planting 8 billion trees every year would sequester a significant amount of carbon dioxide, it would not be able to keep pace with the rate of human-caused emissions.

Additionally, while tree planting can be a useful tool in the fight against climate change, it is not a cure-all solution. Planting trees in the wrong places, such as in areas prone to wildfire or where they may displace wildlife, can have negative consequences. Furthermore, the benefits of tree planting are limited by the fact that trees take decades to mature and reach their full carbon sequestration potential.

It's important to note that planting trees is one of the many things that should be done to combat climate change. Reducing greenhouse gas emissions from fossil fuels, increasing the use of renewable energy, sustainable land use practices, and investing in technology for Carbon capture and storage are all crucial steps that need to be taken in order to effectively address the scale of the climate crisis.

In summary, planting 8 billion trees every year for 25 years would certainly have a positive impact on Earth's climate, but it would not be sufficient to fully offset the effects of human activity on the planet. It is an important step in the fight against climate change, but it must be accompanied by a comprehensive and sustained effort to reduce greenhouse gas emissions and implement sustainable practices.

Furthermore, the cost, the land required, maintenance, and the potential impacts on local communities, as well as the potential negative impact on biodiversity should be carefully considered. Planting trees must be done in a strategic, science-based and sustainable manner.