Wherever you live, if you remember last summer, this probably won’t surprise you. Earth’s average surface temperature in 2022 tied with 2015 as the fifth warmest on record, according to a recent analysis by NASA. In a continuation of the planet’s long-term warming trend, global temperatures in 2022 were 1.6 degrees Fahrenheit above the average for the baseline period of 1951 to 1980.
But I’m not going to tell you that this is “the new normal” or a hopeless situation. We can—and already have!—done something about it. New research shows that a 1987 global treaty, designed to protect the ozone layer, has postponed the occurrence of the first ice-free Arctic by as much as 15 years. That’s huge.
And we have the potential, right now, to do more. About a quarter of the world’s electricity currently comes from power plants fired by natural gas. That contributes significantly to global greenhouse gas emissions (amounting to 10 percent of energy-related emissions, according to the most recent figures from 2017) and climate change. The total global carbon dioxide (CO2) emissions from the life cycle of gas-fired power is 3.6 billion tons each year. But we can reduce this amount by as much as 71 percent if a variety of mitigation options are used around the world.
2015 and 2022 tied for fifth place
According to scientists from the NASA Goddard Institute for Space Studies, the past nine years have been the warmest since modern recordkeeping began in 1880. In 2022, Earth was about 2 degrees Fahrenheit warmer than the late 19th century average. We can certainly see the marks of a warming climate all around us: droughts are getting more severe, forest fires are intensifying, hurricanes and tropical storms are getting stronger, and sea levels are rising. Last year brought torrential monsoon rains that devastated Pakistan and a persistent megadrought in the U.S. Southwest. In September, Hurricane Ian became one of the strongest and costliest hurricanes to strike the continental U.S.
NASA collects its global temperature data from weather stations and Antarctic research stations, as well as instruments mounted on ocean buoys and ships. The agency’s scientists then analyze these measurements to account for uncertainties and to maintain consistent methods for calculating global average surface temperature differences for every year. These ground-based measurements of surface temperature align with satellite data collected since 2002 by the Atmospheric Infrared Sounder on NASA’s Aqua satellite and with other estimates. The period from 1951 to 1980 is used as a baseline to understand how global temperatures change over time. That baseline includes climate patterns, such as La Nina and El Nino, as well as unusually cold or hot years due to other factors, ensuring it encompasses natural variations in Earth’s temperature.
Scientists say there’s no doubt that the reason for the warming trend is that human activities continue to pump enormous amounts of greenhouse gases into the atmosphere. Although there was a short-lived dip in 2020 due to the COVID-19 pandemic, human-driven greenhouse gas emissions have rebounded in a big way. Recently, international scientists and NASA scientists determined that carbon dioxide emissions were the highest on record in 2022. The Arctic region continues to experience the strongest warming trends—close to four times the global average.
Montreal Protocol made a monumental difference
But in this current context of our heating-up planet comes some hard evidence about a positive change we’ve already made—and how we can make more.
When scientists discovered a hole in the ozone over Antarctica in 1985, countries across the globe got together and wrote a treaty designed to protect the ozone layer, which shields the Earth from harmful levels of ultraviolet radiation. The resulting Montreal Protocol—the only United Nations treaty ratified by every country in the world—was signed in 1987. It entered into effect in 1989, when little was known about its impact on the global climate. Its purpose was to reduce atmospheric concentrations of ozone-depleting substances (ODSs), materials commonly used in products such as aerosols, air conditioners, fire extinguishers and refrigerators. For more than 30 years, it has been an important mitigation treaty, affecting many aspects of the global climate.
The rapid melting of Arctic sea ice is one of the largest and clearest signals of anthropogenic climate change. Recent projections have been that the first ice-free Arctic summer will occur by 2050, owing largely to increasing carbon dioxide concentrations in the atmosphere. However, other powerful greenhouse gases have also contributed to Arctic sea-ice loss, notably ODSs. ODS molecules, while a lot less common in the atmosphere, are tens of thousands of times more powerful at warming the planet than carbon dioxide. But when ODSs became strictly regulated by the Montreal Protocol in the late 1980s, their atmospheric concentrations began to decline, starting in the mid-1990s.
Now, a new study, published in May 2023 in the science journal Proceedings of the National Academy of Sciences of the United States of America and led by climate researchers at New York’s Columbia University and England’s University of Exeter, demonstrates that the Montreal Protocol’s impact reaches all the way into the Arctic: its implementation is delaying the occurrence of the first ice-free Arctic by as much as 15 years, depending on the details of future CO2 emissions.
The researchers compared the estimated warming from ODSs with and without the Montreal Protocol under two scenarios of future CO2 emissions from 1985 to 2050. Their results showed that if the Montreal Protocol had not been enacted, the estimated global mean surface temperature would be almost 1 degree Fahrenheit warmer, and the Arctic polar cap would be almost 2 degrees Fahrenheit warmer in 2050. This important climate mitigation stems entirely from the reduced greenhouse gas warming from the regulated ODSs.
Thus, while ODSs aren’t as abundant as other greenhouse gasses such as carbon dioxide, they can have a real impact on global warming. ODSs have particularly powerful effects in the Arctic, and they were an important driver of Arctic climate change in the second half of the 20th century. While stopping these effects was not the primary goal of the Montreal Protocol, it has been a fantastic, positive by-product.
Reducing greenhouse gas emissions is achievable
There’s more hope on the horizon: we can still reduce our greenhouse gas emissions—by a lot.
By gathering data from 108 countries around the world and quantifying the emissions from each country, a research team from McGill University in Montreal, Canada, estimates that total global carbon dioxide emissions from the life cycle of gas-fired power is 3.6 billion tons each year. This amount could be reduced by as much as 71 percent if a variety of mitigation options are used around the world.
Publishing their work in the science journal Nature Climate Change in October 2022, the researchers say that they were astonished by how large the potential reduction in greenhouse gases could be by 2050—and even by 2030—by cutting methane emissions from natural gas production, using carbon capture and storage, followed by making power plants more efficient.
The mitigation options that will be most successful in any given country, of course, will vary depending on the regional context and the existing infrastructure. The research team calculated that the largest mitigation potential (39 percent) lies with five biggest emitters: the United States, Russia, Iran, Saudi Arabia and Japan; all of whom, except for Japan, are among the largest gas consumers and producers around the world.
Rapid warming responds to remedies
Climate change is a global challenge. Achieving a low-carbon energy system worldwide means that we will need to reduce emissions across the supply chain, from gas extraction through end use. It will take significant efforts to transition from current emission levels, but by identifying the drivers of emissions in the gas supply chain, governments will be able to take strategic, nationally determined actions to reduce their emissions.
And the Montreal Protocol points the way. It’s delaying the melting of Arctic sea ice at this very moment, and there are signs that the ozone layer has started to heal. That’s what successful climate treaties do: they yield measurable results within a few decades of their implementation.
The fact is that the Earth is rapidly warming in response to our activities. But here’s what gives me hope: we now know that the planet will react to our remedial efforts.
I suggest we make some more of them—and soon.
Here’s to finding your true places and natural habitats,