Climate commitment

[4]: 2222 If a perturbation — such as an increase in greenhouse gases or solar activity — is applied to Earth's climate system the response will not be immediate, principally because of the large heat capacity and thermal inertia of the oceans.

Also once a certain threshold is crossed, it is likely that a slow melting of the Greenland ice sheet will commit us to a sea level rise of 5m over millennia.

[citation needed] Recent models forecast that even in the unlikely event of greenhouse gases stabilizing at present levels, the Earth would warm by an additional 0.5°C by 2100, a similar rise in temperature to that seen during the 20th century.

These models do not take into account ice cap and glacier melting; including those climate feedback effects would give a 1–1.5°C estimated temperature increase.

Climate commitment studies span a range of emissions scenarios which are intimately tied to past, present and future human choices.

The ongoing buildup of long-lived greenhouse gases in Earth's atmosphere, whose warming influence has nearly doubled since 1979, shows mankind's influence on the global climate. [ 1 ] [ 2 ] [ 3 ]
The accumulation of excess heat in the ocean , at ever greater depths, measures global warming that has already become "irreversible" in the near term [ 5 ]