The Greater Disaster

In the midst of the pandemic, Andrew Glikson reminds us of another catastrophe in progress.

Carbon dioxide is now pouring into the atmosphere at a rate of two to three parts per million each year.

My research has demonstrated that annual carbon dioxide emissions are now faster than after both the asteroid impact that eradicated the dinosaurs (about 0.18 parts per million CO2 per year), and the thermal maximum 55 million years ago (about 0.11 parts per million CO2 per year).

[T]he massive influx of carbon dioxide means the climate is changing faster than many plant and animal species can adapt.

[O]n the current trajectory, human activity threatens to make large parts of the Earth uninhabitable - a planetary tragedy of our own making.

Andrea Marks and Hannah Murphy document some of the species now facing extinction.

Global warming has set off a cascade of disruptions to the web of life, changing animals' breeding habits, food supply, and their very DNA. They are in distress not only from climate instability but also from the loss of habitat and pollution produced by unchecked human consumption. In the past century, species have been wiped out at a pace 100 times greater than the natural rate of extinction, and as many as 1 million species are at risk of going extinct in the coming decades, according to a United Nations report released last spring. There is perhaps no better bellwether of the peril we face than this dwindling biodiversity. "The evidence is crystal clear," said Sandra Díaz, one of the co-chairs of the U.N. report. "Nature is in trouble. Therefore, we are in trouble."

Update (April 15):  Robert Hunziker points to a study published in Nature that anticipates "a potentially catastrophic loss of global biodiversity". Lead author Christopher Trisos:

The main finding that surprised us was how much biodiversity is at risk in the first half of this century. The risk doesn’t accumulate gradually, but can go from low risk to high risk within a decade. This abruptness of risk was really a shocking finding for us.

Update (May 23):  Hunziker quotes John Doyle (and we only hope he is way off track):

We’re actually heading for 10 degrees warming that could happen within 20 to 30 years. And, on the way to 10 degrees, we pass 4 degrees. Now, four degrees is interesting because that’s extinction for our species.

Update (June 2):  A study published by PNAS points to COVID-19 as an example of growing human pressure on the biosphere.

The ongoing sixth mass extinction may be the most serious environmental threat to the persistence of civilization, because it is irreversible. Thousands of populations of critically endangered vertebrate animal species have been lost in a century, indicating that the sixth mass extinction is human caused and accelerating. ... Our results reemphasize the extreme urgency of taking massive global actions to save humanity's crucial life-support systems.

Lead author Gerardo Ceballos:

The vaccine for Covid-19 was natural habitat. The pandemic is a great example of how badly we’ve treated nature.

Update (June 8):  With the warmest February on record, the Great Barrier Reef saw the most extensive bleaching event in March.

Update (July 11):  A report from the World Meteorological Organization gives a 70 percent probability that some month within the next five years will exceed a 1.5 degree Celsius increase over pre-industrial temperatures and a 20 percent probability that a given year in that period exceeds that threshold.

Update (October 13):  A study published in the Proceedings of the Royal Society B finds that half the corals in the Great Barrier Reef have died since the 1990s.

The loss of so many corals along nearly every section of the 1,600-mile reef is shocking. Larger corals can take years or decades to grow, and effectively act as both the parents and home for a new generation of coral polyps that replace them. The researchers analyzed the number of corals along sections of 30 reefs up and down the Great Barrier 20 years apart, in 1996 and in 2016, and found populations of elder, adolescent and baby corals had all fallen by more than 50% in just 20 years.

Update (October 7, 2021):  A report from the Global Coral Reef Monitoring Network finds that 14 percent of coral reefs were lost between 2009 and 2018.