The persistent march of a warming climate is seen across a multitude of continuous, incremental changes. CO2 levels in the atmosphere. Ocean heat content. Global sea-level rise. Each creeps up year after year, fuelled by human-caused greenhouse gas emissions.
And while climate records are being routinely broken, the cumulative impact of these changes could also cause fundamental parts of the Earth system to change dramatically and irreversibly.
These “tipping points” are thresholds where a tiny change could push a system into a completely new state.
Imagine a child pushing themselves from the top of a playground slide. There is a point beyond which it is too late for the child to stop themselves sliding down. Pass this threshold and the child continues inevitably towards a different state – at the bottom of the slide rather than the top.
In this article, Carbon Brief explores nine key tipping points across the Earth system, from collapsing ice sheets and thawing permafrost, to shifting monsoons and forest dieback.
A glance at the news media on any given week will likely highlight all sorts of climate change impacts. From declining Arctic sea ice and record-breaking heatwaves to melting glaciers and worsening droughts, the increase in global average temperature is being felt around the world.
Broadly, these impacts reflect gradual changes caused by a climate that is steadily warming. Scientists have estimated, for example, that for every tonne of CO2 emitted into the atmosphere, summer sea ice cover in the Arctic shrinks by three square metres.
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