New dinosaur fossils could belong to the largest creature to walk on Earth

Our evolution has chosen a ‘fight or flight’ instinct to deal with environmental change, so much like the metaphor of the frog in boiling water, we tend to react too little and too late to gradual change.

< p> Climate change is often described as global warming, with the implication of gradual changes caused by a steady increase in temperatures; from heat waves to melting glaciers.

But we know from multidisciplinary scientific evidence – from geology, anthropology, and archeology – that climate change is not gradual. Even in prehuman times, it is episodic, when it is not forced by an acceleration of greenhouse gas emissions and human-induced warming.

There are parts of our planet’s carbon cycle, the ways in which the earth and the biosphere store and release carbon, which could be triggered suddenly in response to gradual warming. These are tipping points that, once passed, could fundamentally disrupt the planet and produce abrupt, non-linear changes in climate.

A game of Jenga

Think of it as a game of Jenga and the planet’s climate system as the tower. For generations, we have been slowly removing blocks. But at some point we will remove a pivotal block, such as the collapse of one of the world’s major ocean circulation systems, for example the Atlantic Meridional Reversal Circulation (AMOC), which will cause all or part of the global climate system. in a planetary emergency.

But even worse, it could cause uncontrollable damage: where the tipping points form a domino-like waterfall, where the breach triggers the violation of others, creating an unstoppable passage to a drastic and rapid climate change situation.

One of the most worrying tipping points is the massive release of methane. Methane can be found in freezing storage in permafrost and at the bottom of the deepest oceans as methane hydrates. But rising sea and air temperatures are starting to thaw these methane reserves.

This would release a powerful greenhouse gas into the atmosphere, 30 times more powerful than carbon dioxide as a global warming agent. This would dramatically increase temperatures and rush us into the breach of other tipping points.

This could include the acceleration of the ice thaws on the three major land ice caps of the globe – Greenland, West Antarctica and the Wilkes Basin in East Antarctica. The potential collapse of the West Antarctic ice sheet is seen as a key tipping point, as its loss could eventually raise the world sea level by 3.3 meters with significant regional variations.

In addition, we would be on the irreversible path of complete melting of land ice, causing sea levels to rise up to 30 meters, at roughly the rate of two meters per century, or perhaps faster. One need only look at elevated beaches around the world, at the last high level of global sea level, at the end of the Pleistocene period about 120,0000 years ago, to see evidence of such a hot world, which was only 2 ° C warmer than today.

Cut off traffic

In addition to wreaking havoc on low-lying and coastal areas around the world, melting polar ice could trigger another tipping point: a deactivation of AMOC.

This circulation system results in a northward flow of heat, salt water over the upper layers of the ocean from the tropics to the northeast Atlantic region, and a southward flow of cold water to the bottom of the ‘ocean.

The ocean conveyor belt has a major effect on the climate, seasonal cycles and temperature in Western and Northern Europe. This means that the region is warmer than other areas of similar latitude.

But the melting ice of the Greenland ice cap could threaten the AMOC system. This would dilute the salty sea water in the North Atlantic, making the water lighter and less able or unable to sink. This would slow down the engine of this ocean circulation.

Recent research suggest that AMOC has already weakened by around 15% since the mid-20th century. If this continues, it could have a major impact on the climate of the northern hemisphere, but particularly of Europe. It can even lead to cessation of arable land agriculture in the UK, for example.

It can also reduce precipitation over the Amazon Basin, impact monsoon systems in Asia and, by bringing warm waters into the Southern Ocean, further destabilize the ice in Antarctica and accelerate sea level rise. in the world.

Is it time to declare a climate emergency?

At what point and at what rise in global temperatures will these tipping points be reached? No one is entirely sure. It may take centuries, millennia, or it could be imminent.

But as COVID-19 has taught us, we need to prepare for expectations. We were aware of the risk of a pandemic. We also knew that we were not sufficiently prepared. But we did not act in a meaningful way. Fortunately, we have been able to speed up the production of vaccines to fight COVID-19. But there is no vaccine for climate change once we get past these tipping points.

We must act now on our climate . Act as if these tipping points are imminent. And stop seeing climate change as a slow, long-term threat that allows us to fix the problem and let future generations deal with it. We must take immediate action to reduce global warming and honor our commitments to Paris Agreement and build resilience by keeping these tipping points in mind.

We need to plan now to mitigate greenhouse gas emissions, but we also need to anticipate the impacts, such as the ability to feed everyone on the planet, making plans to manage flood risk, as well as managing the social and geopolitical impacts of human migrations which will be a consequence of the decisions to fight or to flee.

Violation of these tipping points would be cataclysmic and potentially much more devastating than COVID-19. Some may not like to hear these messages or consider them to be science fiction. But if it instills a sense of urgency to make us respond to climate change like we did the pandemic, then we need to talk more about what happened before and will happen again.

Otherwise, we will continue to play Jenga with our planet. And ultimately, there will only be one loser – us.

Republished with permission from World Economic Forum.