Climate 101, a Mashable series answers provocative and important questions about Earth’s warming climate.
Nearly 110 years ago, a New Zealand newspaper warned that carbon emissions from burning fossil fuels in the great “furnaces of the world” would raise Earth’s temperature. “The effect may be considerable in a few centuries,” the paper wrote.
This was an acceptable prediction. It turned out that a significant climate change has taken place faster than expected, within just over a century. Earth scientists anticipate impacts such as severe droughts and rapid-spreading wildfires and destabilized Antarctica ice sheets — which will only get worse with increasing global warming.
On Monday, the UN’s Intergovernmental Panel on Climate Change, or IPCC, published its clearest picture yet on the updated science of planetary heating. Nearly 4,000 pages of the report were authored by scientists representing 66 countries (plus 500 additional contributors). It emphasizes that global warming is widespread, and it’s intensifying. However, humanity can take action to prevent its worst effects.
Linda Mearns, a senior scientist at the National Center for Atmospheric Research who worked as a lead author of the new publication, has worked on IPCC reports for over 25 years. She used to state that climate change was serious and certain.
Mashable told Mearns that “that’s not accurate” It’s serious and certain. And it is now.
It’s serious and certain. And it is now.
Mearns stated that “Hopefully, this report will make an impact in terms of showing urgency.”
These are the main points in the Climate Report:
The extreme weather conditions are becoming more severe
Mashable: “Both frequency and intensity increase of many extremes in climate,” Greg Flato (a senior researcher scientist at the Canadian government, who organized the IPCC Report), said.
For example, as the climate warms the atmosphere can hold more water, resulting in increasingly heavy downpours. According to the report, the highest precipitation “increased” since 1950s in most areas where observational data is available. This includes large parts of North America as well as Europe.
But extremes don’t always act alone.
Mearns stated that “one of the most important messages from the report is to emphasize extreme but especially compound extreme events.” When more than one extreme occurs at the same time, it is called a compound extreme event.
One example is the current Western U.S. fires. The West is experiencing unnatural fires due to the combination of high temperatures and poorly managed forests. Yet drought — made worse by warmer temperatures and heat waves — further parches the land and evaporates moisture from forests and vegetation, creating more fuel ready to burn. What does this mean? The result?
Mearns stated, “Those are quite a few heavy-duty extremes.”
The science is right for decades
Climate scientists and Earth scientists know for many decades that human activity is causing rapid global warming. This has had predictable results like increasing sea levels and more extreme heat.
Flato stated that “this report truly confirms information which was previously available,” and he noted the addition of climate analysis and observations in the latest IPCC publication. Flato stated that “Human influences have caused climate change”, is the main conclusion of all research.
Other recent events, such as prodigiously active sunspots and erupting volcanoes, have not caused the climate to warm rapidly. In fact, during the last four decades the sun’s output has slightly decreased, while Earth warmed.
The IPCC stated that “it is unambiguous that human influence has heated the atmosphere, oceans and land.”
Data on Earth’s acceleration of warming is abundant and obvious.
Since the late 1800s, the planet has already warmed by 2 degrees Fahrenheit (or 1.1 Celsius), though regionally many areas on land have warmed significantly more. NASA uses over 26,000 weather stations and thousands of ocean sensors to monitor warming temperatures. The IPCC stated that since 1990’s first IPCC Report, large numbers have been added to the collection of data from the sky, land and sea.
Oceans changing rapidly and in unsettling ways
It is easy for land-based humans to forget that Earth is an oceanic planet that is dominated by marine creatures. A chapter in the UN’s latest report is dedicated to ocean changes. These changes, because they’re happening rapidly compared to the gradual, natural climate changes of the past, adversely impact civilization (especially along the coasts) and life in the seas. It’s not like turning a switch.
Rising sea levels are a clear and predictable consequence of warming temperatures. Thick masses of ice, frozen on Antarctica, Greenland, and mountains, are melting into the ocean. Already, sea levels globally have risen by some eight to nine inches since the late 1800s. These changes will not be reversed over the next thousands of years.
Flato stated, “It is one of the most important aspects of climate change that are effectively irreversible.”
Sea levels rose faster in the 20th century than in any prior century over the last three thousand years, the IPCC found, based on research of fossilized coastal creatures. The IPCC projects that sea level will continue to rise until the end of this century, assuming intermediate carbon emissions (not very high or low).
Other important changes are also expected in the oceans, but they will not be as severe if carbon emissions are reduced this century.
The IPCC stated that the Arctic Ocean “likely will become practically sea-ice-free” by 2050 after many Arctic summers. This has giant implications for weather, climate, and Arctic life.
Even if emissions of carbon dioxide are greatly reduced, the oceans will still continue to heat for many centuries. They absorb more than 90 percent of Earth’s heat. Warming oceans will lead to more rapid melting and profound habitat problems for marine life. It also means that hurricanes are likely to become more common.
Heat waves in the ocean — extreme and long-lasting warm temperatures — have become more common over the past century, and they will continue to be more frequent next century.
The ocean is losing oxygen as the climate warms, which is problematic for sea life that relies heavily on oxygen to function.
The ocean is growing more acidic as it absorbs more CO2, which will harm marine life, particularly species that can’t adapt to a notable surge in acidity.
The future is ours.
Earth’s future will be determined largely by how much heat-trapping carbon we emit into the atmosphere in this century. More carbon means more severe impacts, especially in extreme weather conditions.
Flato stated, “Every little warming we allow to occur increases these devastating extreme events.”
We can limit global warming to much lower levels, but that is not the most important point.
Already, Earth (whose atmosphere is loaded with the highest levels of heat-trapping carbon dioxide in some 3 million years) will continue warming through at least mid-century, even if society radically cuts carbon emissions, the IPCC said. The agency finds Earth’s temperature may creep 2.7 F (1.5 C) above 19th century levels — the extremely ambitious goal agreed to by global nations at the historic Paris agreement — sometime in the early 2030s.
The IPCC stated that “global warming of 1.5degC to 2degC would be exceeded in the 21st Century unless there are deep cuts in CO2 emissions in the next decade.”
It is important to remember that warming can be controlled at much lower levels. For instance, stabilizing global temperature around 3.6 F (2 C), above the 19th century levels, would result in a lot less extreme than aiming for 5.4 F (3 C).
Avoiding the worst impacts of climate change requires systemic, societal changes. People can make better climate and energy decisions if they have the ability to do so — like a nationwide plan to vastly expand electric vehicle charging stations to spur EV adoption.
This is a difficult task in an age where fossil fuels dominate society. “Even a homeless person living in a fossil fuel-powered society has an unsustainably high carbon footprint,” Benjamin Franta, who researches law and history of science as a J.D.-Ph.D. student at Stanford Law School, told Mashable last year. Food, transport, and everything else we rely on old, carbon-rich fossil fuels.
This is the clear picture.
Richard Spinrad, administrator of the National Oceanic and Atmospheric Administration, stated in a statement that “we have a very narrow window to prevent very costly, fatal, and irreversible climate impacts.” Scientists around the globe agree that strong and sustained greenhouse gas reduction is necessary.
Publiated at Tue 10 August 2021, 02:02:00 +0000