Climate change is slowing the conveyor belt of ocean tides that transports warm waters from the tropics into the North Atlantic. A study published today in Nature Climate Change (June 6) examines the effects of a collapsed Atlantic conveyor on global climate. Researchers found that the Earth’s atmosphere could shift to a La Nia-like state if the mechanism, known as the “Atlantic overturning circulation,” collapses. While climate warming has increased moisture in the Researcher’s atmosphere, La Nia has warmed up the ocean in northern Australia over the past two summers. In eastern Australia, flooding and severe droughts in the southwest US would be expected. La Nia can have devastating effects on the East Coast of Australia. Some of the wettest conditions in history were caused by record-breaking floods in Queensland and New South Wales. Drought and bushfires in Southwest North America have caused severe damage to agriculture and emergency services. The 2021 fires alone cost an estimated $1Billion.
Atlantic turns meridional circulation.
The Atlantic upsetting movement is a large glide of warm tropical waters from the North Atlantic. This allows the European climate to remain moderate and the tropics to lose excess heat. The Southern Hemisphere has an equivalent upsetting of Antarctic waters. Climate statistics that have achieved a 120,000-year record reveal that the Atlantic overturning stream is now stopped or has slowed down for a significant period. It turns on European weather and calms it during so-called ‘interglacial durations,’ while the Earth’s temperature is higher. The Atlantic overturning was relatively stable because human civilization started 5,000 years ago. Scientists have noticed a slowdown over the past few decades.
Why slow down?
The specific result of global warming is the melting of the polar ice cap in Antarctica and Greenland. These ice caps melt and release vast amounts of freshwater into oceans. This makes water lighter and lowers the sinking rate at high altitudes. Greenland’s massive 5 trillion tons of ice has melted in the last 20 years. This is equivalent to 10,000 Sydney Herbs of freshwater. If international warming continues to accelerate, this melt fee will continue to rise over the next decades. The anatomy of the oceans could be drastically altered by the collapse of the Antarctic, North Atlantic, and circulations.
The effects of a slowdown
Researchers used an international model to examine Earth’s climate if it experienced the same level of disintegration as it did. Researchers used a significant North Atlantic meltwater anomaly to turn off the Atlantic overturning. Researchers then compared it to an identical run without melting water. Researchers began to notice that there were other impacts on Europe and North America, and they wanted to see how climate could change far away. The Atlantic turning did not cause one issue the simulations revealed the massive buildup of heat south of the Equator. The excess tropical Atlantic heat causes more warm, wet air to rise into the upper troposphere, which causes dry air to fall over the east Pacific.
The descending air pushes warm water towards the Indonesian coasts, strengthening exchange winds. This allows the tropical Pacific to be similar to La Nina. Australians may imagine la Nina’s summers to be cool and wet. Their worst effects, particularly over the east, can be flooding rains, especially if they are below the long-term trend of weather alter.