Due to anthropogenic carbon emissions, the Earth will be surpassing 1.5°C warming sooner rather than later, according to a report recently released by the World Meteorological Organization (WMO). The rise in average global temperatures, even by each half a degree, caused by unchecked greenhouse gas emissions has caused the Earth’s climate systems to change, including ocean circulation and currents, regional variations in weather, and naturally-occurring feedback mechanisms.
The 1.5°C Threshold and Global Warming
Global warming refers to the long-term average temperature rise of the Earth caused by human activities that spewed greenhouse gas (GHG) emissions, namely carbon dioxide from burning fossil fuels, into the atmosphere. Scientists predict that is 66% likely that the Earth’s average global temperature will cross the 1.5°C pre-industrial threshold, even if temporarily, between now and 2027. Additionally, at least one of the next 5 years have a 98% likelihood of being the warmest year on record as well as the next 5 years overall.
This 66% probability has increased even from a year ago, when the WMO researchers predicted a 50:50 chance with the caveat that this probability could be even higher within the next few years. In 2020, the WMO predicted that this chance was only 20% of reaching this threshold, but by 2023 it has jumped to 66% of more than likely occurring within the next few years. By 2016, average global temperatures reached 1.28°C above pre-industrial averages.
Reaching this 1.5°C global warming threshold means that the planet will be hotter than the second half of the 19th century before human activities released vast amounts of carbon emissions into the atmosphere after burning fossil fuels. The chances of average global temperatures rising above this temperature threshold are due to not mitigating carbon emissions quickly or effectively enough to reduce them by 43% by 2030 in addition to a strong El Niño cycle. However, reaching the 1.5°C average global warming temperature is of serious concern, even if it’s only occurring for a year or two over the next decade. It may be here to stay.
Previously, scientists were concerned with crossing the 2.0°C threshold as the tipping point for dangerous climate change impacts around the world. But in 2018 based on research, they lowered this threshold to 1.5°C as the precipice for calamitous consequences for the Earth. Even with each half a degree of warming, the rise in average global temperatures will have significant impacts for the environment, ecosystems, and human civilization, such as mass coral bleaching events, changes in rainfall patterns, and shifts in species’ distribution altering migration patterns and ecosystems services.
Researchers identified 8 earth system boundaries, with their research published in the Nature journal: climate, biodiversity, water, natural ecosystems, land use and the effect of fertilizers and aerosols. As a part of the Earth Commission, they have proposed “safe and just Earth systems boundaries” that considers the impact on planet and people for global temperature rise greater than 1°C degree. Some of the metrics include: 34% of the land area where the natural streamflow is impacted by more than 25%; only 45–50% of land area is covered by largely intact ecosystems; and only 36% of urban and agricultural land area where at least 20% of every square kilometers is semi-natural habitat. Concerningly, even at 1.2°C rise in average global temperature, some scientists consider the Earth past its safe limits for humans due to disruptions to ecosystems, destructions of natural habitats, and changing water systems.
The Impact of El Niño on Global Warming
Further, scientists have widely recognized that the Earth is warming unequivocally, caused by increases in historical and current anthropogenic emissions since the Industrial Revolution. This period of global warming will be enhanced by the very likely development of El Niño in the tropical zone of Pacific Ocean of the West Coast of the Americas.
El Niño is a climate pattern characterized by warmer-than-average sea surface temperatures in the central and eastern equatorial Pacific Ocean, which is part of a larger climate phenomenon known as the El Niño-Southern Oscillation (ENSO) cycle that includes La Niña. The unusually stubborn La Nina has ended its 5-year run, enabling the conditions for the El Niño to develop that will change weather and climate conditions around the world for the next several months or a couple of years. However, scientists predict this El Niño to be a stronger climate pattern than in years past and 90% likely to last through the end of 2023 and into the first months of 2024.
When combined with climate change impacts, El Niño cycles can cause havoc in regions around the world, such as damaging extreme weather like massive flooding events in the U.S. An El Niño cycle changes weather patterns and other problems impacting humans, including altering the moisture-rich air currents in the atmosphere causing a warmer and drier winter in North America, flooding in the South American deserts, drying up the monsoon in Indonesia, disrupting fish migration patterns, and enhance the spread of infectious diseases. Researchers estimate El Niño will cost the global economy as much as $3.4 trillion in economic losses over the next five years.
Wide-Ranging Global Warming Impacts Around the World
With the combination of a rapidly warming world and a strong El Niño system, the international community understands the serious nature of rising temperatures and unmitigated GHG emissions, especially carbon dioxide emissions. The 1.5°C temperature threshold is a symbol and a legal commitment for the international community through the ratification of the Paris Agreement that passed in 2015. The international community agreed to limit global warming to only 1.5°C above pre-industrial levels of emissions because crossing this temperature threshold will have dire consequences. Researchers have clarified that the Earth has to maintain this warming for 20 years to determine the goals of the Paris Agreement have failed to curb global warming.
While 1.5°C may not seem like a huge temperature rise, global warming has dire consequences with every half degree of average temperature increase. At a 1.5°C rise, approximately 14 percent of the global population will be impacted with severe heat waves at least once every 5 years; then at 2°C degrees the population affected increases to 34 percent.
Further, global warming does not occur evenly across the planet. In some regions, some land areas are warming faster than others, such as where the polar regions are warming the fastest on the Earth and causing sea ice to melt contributing to sea level rise. High-altitude regions, including the Alps, Andes, and Rockies, are also experiencing warming temperatures than other land regions. These regions are often dependent on snowpack and glaciers for critical water resources. Sub-arctic regions, including Siberia, Alaska and parts of Canada, have experienced rising temperatures that are thawing the permafrost that releases stored carbon and methane emissions into the atmosphere. Coastal areas are particularly at risk from sea level rise and the majority of the Earth’s population living there—up to 410 million people.
Some of the consequences of global warming are significant, harmful, and costly: rising sea levels from melting glaciers, ocean acidification impacting sea life, disruptions in ecosystems that cannot be reversed, changes in weather patterns causing extreme events like severe droughts and heavy rainfall, increase in frequency and strength of typhoons and hurricanes, negative impacts on human health from disease and worsening air pollution, and rising temperatures causing more intense heat waves. The impacts of global warming are interconnected, so curbing greenhouse gas emissions is more important than ever to prevent global warming from going above 1.5°C.
Dire Need to Offset Carbon Emissions More than Ever
As the Earth continues to warm towards the 1.5°C threshold, and combined with a strong El Niño cycle, mitigating carbon and other GHG emissions is vital. The international community, through businesses, governments, individuals, and other organizations can help offset their GHG emissions through voluntary offset programs and carbon markets.