(CN) — Even if the nations of the world stopped all greenhouse gas emissions today, Earth will continue to warm, glaciers and ice caps will continue to melt and oceans will continue to rise for centuries according to a dire study published Thursday.
Human activity has been responsible for almost all greenhouse gas emissions over the past 150 years, which has prevented heat from leaving the atmosphere and contributed to the spike in global temperatures. According to the U.S. Environmental Protection Agency, 28% of all emissions come from transportation, 27% from the production of electricity, 22% from industrial activities, and the rest from businesses and homes, agriculture, and forestry. Of these gases, carbon dioxide is the most prominent, followed by methane — which is 84 times more harmful than CO2 — nitrous oxide and fluorinated gases.
Levels of carbon dioxide in the atmosphere have spiked astronomically since the 1950s, reaching an unprecedented levels that NASA says is increasing 250 times faster than it did from natural causes since the last Ice Age. This has resulted in a sort of blanket surrounding Earth, allowing heat from the sun to enter the atmosphere, but not allowing it to leave. Today, CO2 is mostly released by fossil fuel use and industrial processes.
Policies like the Green New Deal have called for an end to the use of fossil fuels, but scientists now believe that alone will not prevent the further rise of global temperatures. Jorgen Randers, a professor emeritus of climate strategy at BI Norwegian Business School in Oslo, Norway, and his colleagues report that according to their research, global temperatures will continue to rise for centuries even if society could completely eliminate all human-caused greenhouse gas emissions overnight.
In a study published Thursday in the journal Scientific Reports, Randers and his team developed a model that simulated how different reductions of greenhouse gas emissions would affect the world’s climate, including temperatures and sea level. The model exhibited the predicted changes spanning from the years 1850 to 2500.
Assuming human-caused emissions will reach their peak in the year 2030 and are eliminated completely by the year 2100, the model indicates we will still see an increase in global temperatures by 5.4 degrees Fahrenheit and seas that are 10 feet higher than today. Alternatively, the authors say that even if human caused emissions could be eliminated in the year 2020, global temperatures would still spike 5.4 degrees Fahrenheit after a brief decline and oceans would rise 8 feet by 2500.
The study authors warn that as seen in their simulation, these issues could continue to worsen even after manmade emissions are reduced to zero. As glaciers, permafrost, and other ice in Antarctica continue to melt, stored greenhouse gases within them would be released including water vapor, methane and carbon dioxide. Furthermore, they advise that as this ice and permafrost melts, there will be fewer barriers to reflect heat and light from the sun — resulting in even more melting.
If humankind hoped to prevent these negative effects, we would have had to eliminate human-caused greenhouse gas emissions between 1960 and 1970. Mitigating the damage we’ve caused — and avoiding the perils that await us — will be difficult.
The authors say if we want to avoid these scenarios, we need to remove about 33 gigatons of carbon dioxide from the atmosphere every year starting immediately in addition to the complete elimination of manmade greenhouse gas emissions. This can be achieved through promising capture and storage methods developed over the years, and will be our greatest chance at avoiding disaster.
The ill effects of climate change are already being seen worldwide, from significant ice loss and subsequent sea level rises, longer and more harmful heat waves, a substantial spike in frequency of weather-related natural disasters, and more. The Intergovernmental Panel on Climate Change has warned these effects will harm regions of the world disproportionately depending on their ability to adapt and manage them. This could mean disaster for areas struggling economically, coastal areas more prone to dangerous flooding, and those still reeling from the effects of Covid-19.
The IPCC has also warned that the cost of recovering from climate change-related events — repairing storm damage, managing food and housing insecurity and more — will rise with the temperature.
“Taken as a whole, the range of published evidence indicates that the net damage costs of climate change are likely to be significant and to increase over time,” the study authors said in a statement accompanying the study.