Global Warming Threatens the Humanity Directly

United Nations Secretary General Antonio Guterres

This most recent report on the ocean and cryosphere is among dozens released during the last 30 years by the IPCC, but its message is the most bold and urgent to date: If the world's nations do not act with urgency, we - and future generations - will suffer from these changes.

In India, parts of the West Bengal and Odisha coasts are likely to experience such events annually by 2075, according to a map referred to by the IPCC, while the Americas will experience such events even earlier - by 2040. Global warming has already reached 1°C above the pre-industrial level.

The UN report warned that climate change was causing an unprecedented amount of damage to the world's oceans and will cause devastation if emissions are left unchecked, even as acute flooding of several coastal areas has become inevitable no matter whether climate heating emissions are curbed or not.

But the IPCC, a United Nations body, has a number of proposals for policymakers around the world, which it says will build resilience, help adaptation to changes that can no longer be avoided, and provide benefits for sustainable development. Already, sea-level rise and coastal erosion have put two of its nine islands at risk of going underwater. "This will mean higher discharge in rivers, which will also be accentuated by extreme precipitation events", said AL Ramanathan, glaciologist from Jawaharlal Nehru University. By 2100, the ocean will absorb up to two to four times more heat than between 1970 and now if warming is limited to 2°C, and up to five to seven times more at higher emissions.

One of the report's key takeaways are projections for the near-term (2031-2050) and the end of the century (2081-2100), made in contrasting low- and high-emission scenarios.

So-called marine "heat waves" are sweeping across the ocean twice as often as they did three decades ago - with huge implications for marine life, fragile ecosystems, the food chain and the economy.

Glaciers and ice sheets in polar and mountain regions are losing mass, contributing to an increasing rate of sea-level rise, together with the expansion of the warmer ocean.

If fossil fuel use isn't reduced and global warming continues on the present trajectory, the consequences for both wildlife and humans could be catastrophic, according to the IPCC.

On sea ice, the IPCC report underscores that the extent of Arctic ice has declined every month, "and it is getting thinner".

"Co-operation and co-ordination among governing authorities across scales, jurisdictions, sectors, policy domains and planning horizons can enable effective responses to changes in the ocean (and) cryosphere", it says.

One especially worrying example was that extreme flooding could start to occur once a year or more within a century. "By taking a vital role in this milestone report, Carleton is further establishing its leadership in climate change research".

"If we reduce emissions sharply, consequences for people and their livelihoods will still be challenging, but potentially more manageable for those who are most vulnerable", IPCC Chair Hoesung Lee said.

The report notes that while the globe is now locked in to decades of disruption from current greenhouse gas levels, nearly all of the negative effects can be softened by reduced emissions.

While the report says that some factors, like rising sea-levels, might be irreversible by this point, governments can still take decisive action to ward off the worst of climate change.