Here is something you will not hear in the American mainstream media:
“The chance of ‘catastrophic’ climate change completely wiping out humanity by 2100 is now 1-in-20.”
In other words, there is a one in twenty chance humanity will be rendered extinct within the next century from “low-probability high-impact” events resulting from rising global temperatures.
A temperature increase greater than 3°C could lead, according to the study, to “catastrophic” devastating effects. More than a 5°C increase, though, could result in “unknown” apocalyptic consequences.
Veerabhadran Ramanathan, professor of climate and atmospheric sciences at the University of California along with Yangyang Xu, Texas A&M University assistant professor, presents the following analogy:
“When we say five per cent-probability high-impact events, people may dismiss it as small but it is equivalent to a one-in-20 chance the plane you are about to board will crash.”
Ramanathan’s study draws on the Paris Climate accord objective to keep average global temperatures significantly below a 2°C (3.6°F) increase from what they were prior to the Industrial Revolution.
The risk category “dangerous” is based on guidelines the Intergovernmental Panel on Climate Change (IPCC) and previous independent studies established.
“New Climate Risk Classification Created to Account for Potential ‘Existential’ Threats,” published on the Scripps Institution of Oceanography website, explains the “dangerous” category as follows:
“’Dangerous’ global warming includes consequences such as increased risk of extreme weather and climate events ranging from more intense heat waves, hurricanes, and floods, to prolonged droughts. Planetary warming between 3°C and 5°C could trigger what scientists term ‘tipping points’ such as the collapse of the West Antarctic Ice Sheet and subsequent global sea-level rise, and the dieback of the Amazon rainforest. In human systems, catastrophic climate change is marked by deadly heat waves becoming commonplace, exposing over 7 billion people to heat related mortalities and famine becoming widespread.’
The “unknown” category is not included in the IPCC assessment, nor is the 5°C increase projection. Ramanathan and Xu created the “unknown??” category, with question marks, to indicate the “subjective nature of our deduction.”
Under this umbrella, existential threats may include species extinctions, severe threats to water and food supplies, and health risks when over seven billion people worldwide are subjected to deadly heat.
The earth has not experienced warming beyond five degrees Celsius in at least 20 million years. Hitting this tipping point would likely pose an existential threat to humanity.
So, what do we do? Party like there’s no tomorrow for the next 83 years?
We could, but the researchers suggest we take aggressive measures to curtail fossil fuel use and emissions of so-called “short-lived climate pollutants,” like soot, methane, and hydrofluorocarbons (HFCs) through extracting carbon dioxide from the air and sequester it before it can be emitted.
This is attainable, the researchers say.
Between 2000 and 2011, global CO2 emissions grew 2.9 percent per year, but slowed to almost zero by 2015 due to a decrease in CO2 emissions from the United States and China, the primary global polluters. Increases in renewable energy production, especially wind and solar power, have also helped curb emissions. Other studies have estimated by 2015 there was enough renewable energy capacity to accommodate almost 24 percent of demand for global electricity.
California Gov. Jerry Brown (D) collaborated with Ramanathan on carbon neutrality measures in the past.
“This report shines a bright light on the existential threat that climate change presents to all humanity. Scientists have many ideas about how to reduce emissions, but they all agree on the urgency of strong and decisive action to remove carbon from the economy.”
Last February, the Biological Extinction Conference held at the Vatican reported that unless we take immediate urgent action to curb emissions of carbon dioxide and other greenhouse gases, one in five species on Earth faces extinction.
This includes us.
Image credit: Scripps.