Global climate news: March

Select items as presented to Sustainable Gabriola at our March monthly meeting, by Deb Ferens.

Earth on brink of five catastrophic climate tipping points, report warns

  • Greenland & Antarctic ice sheet loss — melting ice
  • Boreal forest permafrost thaw — methane release
  • Atlantic Meridional Overturning Circulation (AMOC) — ocean currents
  • Amazon rainforest
  • Coral reef die-off

We can add: Wildfires and Forest die-off.

The IPCC definition of “Tipping Point” in its 2013-14 fifth assessment report:

  • Passing an irreversible tipping point would mean a system would not revert to its original state, even if the forcing lessens or reverses.

Year 2023 – 2024

  • 2023 — hottest summer on record;
  • Dec 2023-Feb 2024 — warmest Canadian & US winter on record;
  • Sea surface temperatures in North Atlantic Ocean are higher than normal.

Nearly three months into the new year, 2024 is carrying on where 2023 ended: with a litany of broken weather records that include higher air temperatures, warmer oceans, higher tides, and other significant losses such as glacier retreat, Antarctic sea ice loss.


Humans have exceeded 6 of 9 boundaries keeping earth habitable

Earth’s ability to sustain human society depends on nine primary “planetary boundaries,” or global systems that are key indicators of its health. Of these nine limits, humans have blown past six: climate change, biosphere integrity (which includes biodiversity), freshwater availability, land use, nutrient pollution and human-made pollution, such as microplastics and radioactive waste. Only the categories of ocean acidification, air pollution and ozone depletion remain within the constraints.

These boundaries are not “tipping points” that are impossible to return from because they signal humans’ impact on the environment, which we can do something about, such as:

  • reduce the overabundance of phosphorus and nitrogen in Earth’s waters.
  • use no more than 10 percent of plant biomass—currently, we use about 30 percent, for food and fuel.
  • Clean up land and returning forests to late-20th-century levels

Successful actions on this level include the combined global efforts initiated by the Montreal Protocol in 1987 and the resulting recovering of the ozone boundary.

This scale of coordinated change is necessary to address the scale of the climate emergency.


A choice between two tipping points

  • The first is when the Earth’s ecosystems and the life they contain tip into irreversible collapse due to climate change.
  • The second is when the fight for climate action tips from being just one of many political concerns to becoming a mass social movement.

The existential question is, which tipping point will come first?