A couple of definitions will help explain my point.
The point at which an issue, idea, product, etc., crosses a certain threshold and gains significant momentum, triggered by some minor factor or change.
Climate Disruption
The extreme fluctuations that can and will occur to our weather systems as anthropogenic caused carbon dioxide and other green house gases increase in our atmosphere, the oceans get warmer, and weather events become supercharged and less predictable.
How Close Are We to Climate Tipping Points? [Link goes to Columbia Climate School]
A tipping point is the point at which small changes become significant enough to cause a larger, more critical change that can be abrupt, irreversible, and lead to cascading effects. The concept of tipping points was introduced by the IPCC 20 years ago, but then it was thought they would only occur if global warming reached 5°C. Recent IPCC assessments, however, suggested that tipping points could be reached between 1°C and 2°C of warming.
* Bolding mine
The Atmosphere: Getting a Handle on Carbon Dioxide [Link goes to NASA]
Changes to our atmosphere associated with reactive gases (gases that undergo chemical reactions) like ozone and ozone-forming chemicals like nitrous oxides, are relatively short-lived. Carbon dioxide is a different animal, however. Once it’s added to the atmosphere, it hangs around, for a long time: between 300 to 1,000 years. Thus, as humans change the atmosphere by emitting carbon dioxide, those changes will endure on the timescale of many human lives.
As a chemical engineer, I regard the planet as a rotating very complicated batch reactor heated unidirectionally, if we add a reagent change will occur, the rate of change will depend upon the size of the reactor.
The planet as reactors go is of fairly significant size, so the expected rate of change should be reasonably long, i.e. in a geological time frame. The fact that within the human timescale [a matter of decades] we are noticing a massive change [Climate disruption] in global weather norms, this is instantaneous in a geological timeframe suggesting a tipping point has been exceeded/breached.
What CO2 [along with NOx and methane] does is improve the reactor's retention of heat provided by the heat source [i.e. sun] during its diurnal cycle. Adding heat increases the rate of change of reactions within the reactor, for example the loss of the northern and southern ice sheets, which in turn leads to an increased absorption and retention of heat within the reactor.
Heating of the planet also has other knock on consequences, such as the reduction of CO2 absorption by the oceans, thus preventing an equilibrium/CO2 reduction being attained.
Ice Melt at the Poles [ Link goes to the Smithsonian Institute]
It’s confirmed: both Antarctica and Greenland are losing ice—around 350 billion tons each year—and, as a result, sea level has risen 11.1 millimeters worldwide since 1992. This photo shows a summertime channel created by the flow of melted ice, which ultimately carries the water away from the glacier to the sea.
The rate of loss of ice is not constant by increasing annually/decadally i.e. momentum hence inertia.
Arctic Sea Ice Minimum Extent [NASA]
September Arctic sea ice is now shrinking at a rate of 13% per decade, compared to its average extent during the period of 1981 to 2010. This graph shows the size of the Arctic sea ice each September since satellite observations started in 1979.
Even if we hit nett zero by some arbitrarily defined year [i.e.2050] the effects will continue until another climate equilibrium is reached. Will these new climatic conditions permit the natural absorption of CO2? From what we have seen in the last 10 years or so the next 300+ years don’t look promising, after this summer next summer is a scary proposition. What is being done to prepare for this next point?
I suppose we could wait for a milder/cooler style of Venusian greenhouse “climate”. There would of course be no longer a need to worry about the effects of human activity.
PS Tipping Point 1 the mildest of the tipping points.