The human-induced climate change that we are witnessing today is not a temporary phenomenon, but a long-lasting legacy that will affect the Earth for tens of thousands of years, according to a new study.
The study, published in the journal Nature, argues that we have entered a new geological epoch, called the Anthropocene, in which human activities have become the dominant force shaping the planet. The term Anthropocene was coined by Nobel laureate Paul Crutzen in 2000, who suggested that the industrial revolution marked the beginning of a new era in Earth’s history, characterized by the widespread use of fossil fuels, deforestation, urbanization, and population growth.
The study’s authors, led by Professor Simon Lewis from University College London, say that the Anthropocene is not only a scientific concept, but also a moral and political one, as it implies that humans have a responsibility to manage the planet and its resources for the benefit of future generations.
The Longevity of CO2 Emissions
One of the most striking features of the Anthropocene is the unprecedented rise in atmospheric carbon dioxide (CO2) levels, which have increased by more than 40% since the pre-industrial era, reaching over 410 parts per million (ppm) in 2020. CO2 is the main greenhouse gas that traps heat in the atmosphere and causes global warming and climate change.
The study estimates that about half of the CO2 emitted by human activities will remain in the atmosphere for at least 50,000 years, and possibly much longer, depending on how the Earth’s natural carbon cycle responds to the human perturbation. This means that the climate change we have caused is here for at least 50,000 years, and probably far longer, even if we stop emitting CO2 today.
The study also warns that the current CO2 levels are already close to the threshold that could trigger a runaway greenhouse effect, in which the Earth becomes so hot that it loses its ability to cool itself by radiating heat to space. This could lead to a scenario similar to Venus, where the surface temperature is over 400 degrees Celsius and the atmosphere is composed of 96% CO2.
The Implications for the Future
The study urges us to rethink our relationship with the planet and to adopt a more sustainable and equitable way of living. The authors suggest that we need to shift from a linear economy, based on extraction, consumption, and waste, to a circular economy, based on reuse, recycling, and regeneration. They also call for a more democratic and inclusive governance of the global commons, such as the atmosphere, the oceans, and the biodiversity, to ensure that the benefits and costs of the Anthropocene are shared fairly among all people and nations.
The study concludes that the Anthropocene is not a doom-and-gloom scenario, but a challenge and an opportunity to create a better future for ourselves and our descendants. The authors write:
“The Anthropocene is a reminder that we are part of nature, not separate from it, and that our actions have consequences that will last for millennia. It is also a call to action, to use our collective intelligence and creativity to shape the planet in ways that enhance the well-being of all life on Earth.”