How long do we have to reverse climate change?
Mounting evidence indicates anthropogenic (human-caused) greenhouse emissions are responsible for the planet’s warming climate. Reducing emissions is vital to curbing climate change, but mitigation alone isn’t enough: Even if humans immediately cease all greenhouse gas emissions today, climate change will continue. Carbon stays in the atmosphere for decades and even centuries, meaning the full effects of carbon’s heat-retaining capabilities aren’t immediately apparent.
The effects being felt on the planet now — glacial retreat, drought and severe weather events, rising atmospheric temperatures — are the birthing pains of climate change. Current climatic shifts are the initial results of carbon produced since the beginning of the Industrial Revolution. Researchers estimate it takes a decade for peak warming to occur from the time of initial emissions. However, carbon continues to warm the climate for up to 200 years, meaning the majority of warming the planet is experiencing right now is the result of the last half century and, to a lesser extent, the centuries after the Industrial Revolution. In other words, this is just the tip of the iceberg.
According to the International Panel on Climate Change (IPCC), global greenhouse gas emissions have increased nearly two fold since 1970. Industry and fossil fuel combustion for transportation and energy contributed the lion’s share of recent emissions increase. Given exponential increases in carbon emissions since the 70s, and the trend expected to continue in the coming decades, rapid and deep decarbonization of the world’s economy is essential to hedging against catastrophic temperature increase.
The IPCC gives the world a mere 12 years to decarbonize in order to keep global average temperatures on the lower end of imminent heating projections — 1.5°C. To do this, worldwide carbon emissions need to be cut by 45% by 2030 and reach net zero by 2050 as prescribed by the Paris Agreement and the IPCC. The challenges of transitioning from fossil fuel dependency to a carbon-negative economy are huge, as virtually every sector of human society is carbon-based.
Deep decarbonization won’t be cheap. According to Project Drawdown, reaching net zero carbon emissions by 2050 will cost $29,609,300,000,000, or $26.61 trillion. But the cost of doing nothing will be far higher. If business-as-usual continues, global average temperatures could rise 6°C (10.8°F), with disastrous human and ecological consequences. On the flip-side, deep decarbonization, despite its upfront cost, will save the world economy $74.36 trillion by 2050 and keep temperatures within a relatively safe threshold.
Recycling and adopting energy efficient appliances and cars are part of the solution, but simple behavioral changes will not be enough. Reversing current climate trends is essential if the planet hopes to stay within a 1.5°C threshold. This threshold is not arbitrary. As climate expert and co-author of the influential report Trajectories of the Earth System in the Anthropocene Johan Rockström said,
“… scientific robustness … shows 1.5°C is not just a political concession. There is a growing recognition that 2°C is dangerous” (qtd. in The Gaurdian).
Many scientists maintain a “global disaster” is already unfolding at the north and south poles, predicting in just a few years the Arctic may be ice-free at the end of each summer. Because of carbon’s latency period, many experts are concerned the atmosphere could pass a point-of-no-return relatively quickly, resulting in irreversible changes to the planet’s climate.
The world’s carbon budget — and time — are running out. Rapid decarbonization and drawdown are now essential to prevent runaway warming and planetary catastrophe. Thankfully, solutions exist that can be quickly scaled to decarbonize, and budding sectors are poised to further reduce carbon emissions and drawdown carbon already in the atmosphere.
Deep decarbonization starts in the home. Eliminating volatile refrigerants in cooling appliances and reducing food waste are among the highest leverage solutions in reversing climate change. Other high-leverage solutions include implementing wind energy, adopting a plant-based diet, educating girls, investing in solar power, protecting tropical rain forests, and scaling forest-based agriculture (silvopasture). Technologies and infrastructure for these solutions already exist, and are considered “no regrets” measures, meaning they save money and improve quality of life irregardless of their efficacy in reversing climate change.
Nonetheless, without radical transformation of values, infrastructure, and economic mechanisms, reversing climate change will not be possible. As Rockström’s report implores,
“The Stabilized Earth trajectory requires deliberate management of humanity’s relationship with the rest of the Earth System if the world is to avoid crossing a planetary threshold. We suggest that a deep transformation based on a fundamental reorientation of human values, equity, behavior, institutions, economies, and technologies is required.”
