Limiting Global Temperature Rise to 1.5°C Might Not Be Good Enough: Study

A recent study by Science has said that the temperature rise of 1.5°C may trigger Climate Tipping Points (CTPs).

Some Climate Tipping Points may already have been triggered. 

(Photo: AP)

If the post industrial revolution rise in global temperature levels can be limited to 1.5 degrees Celsius, the world has a chance of saving itself from more frequent and severe disastrous extreme weather events and impacts of climate change, reports have said.

Countries around the world have currently been scrambling to achieve climate goals to stay well within the Paris Agreement's 1.5 degrees Celsius threshold, and even that is seeming to be difficult.

However, a recent study by Science has concluded that a temperature rise of 1.5 degrees Celsius might still not be good enough and may trigger certain Climate Tipping Points (CTPs).

1.1 Degrees Celsius Rise in Temperature Already Within Uncertainty Range

Climate Tipping Points are conditions or scenarios beyond which the changes in the climate system may become irreversible and will continue to renew on their own.

Originally, only nine climate tipping points had been identified by scientists in 2009. However, more recently studies have shown that there may be sixteen climate tipping points that currently exist.

For CTPs to actually play out in reality, the global temperatures would have to rise above certain levels, also called temperature thresholds. The thresholds have been catergorised as under 2 degrees Celsius, 2 to 4 degrees Celsius and above 4 degrees Celsius.

The 1.1 degrees Celsius rise in temperature above pre-industrial times is where we are currently and this range is already within the uncertainty range of the lower end of the CTP list.

Which is why we are already seeing the fallouts of climate change, however, these are still relatively mild consequences.

Between the sixteen tipping points, nine have been categorised as core tipping points with the remaining seven being regional tipping elements.

The location of climate tipping elements in the cryosphere (blue), biosphere (green), and ocean/atmosphere (orange), and global warming levels at which their tipping points will likely be triggered.

Photo: Science

Ocean Levels Already on the Rise

There are a few of these tipping points that we may have crossed already. According to research done in the past decade, we may be at risk of the 'grounding line' of the Amundsen Sea embayment of West Antarctica retreating. This change in the climate system will be irreversible.

The 'grounding line' is the point at which glaciers and ice shelves start to float, separating from the bedrock.

Another major concern is that the East Antarctic ice sheet may also be in an unstable state. If it continues to melt, there may be a rise of 3-4 meter over the current sea level.

Meanwhile, the Greenland ice sheet is continuing to melt at an accelerated rate, according to a study published in Nature.

If the ice sheet melts entirely, the world is at risk of another 7 meter rise above the current sea level. Experts have suggested that the ice sheet is already at risk of melting even at the 1.5 degrees Celsius temperatures.

If the ocean levels do increase this could severely affect aquatic biodiversity, more specifically coral reefs and threaten human lives and livelihoods.