Scientists say a big ocean current is slowing down because of climate change

Apr 25, 2026, 08:00

Introduction

The Atlantic Meridional Overturning Circulation (AMOC) is a big system of ocean currents. It moves warm water from the south to the north. This warm water helps keep Europe warm. Scientists now think the AMOC may slow down a lot by the year 2100. But they do not think it will stop completely.

Main Body

The AMOC works like a conveyor belt. Warm water moves north. In the north, the water cools and becomes heavier. It sinks and then moves south again. This process makes Europe warmer than other places at the same latitude, like Canada. It also helps sea animals by moving food in the water. Climate change is causing problems. The ocean is getting warmer. Ice from Greenland melts and adds fresh water to the ocean. This makes the water less salty. When the water is less salty, it does not sink as much. So the current slows down. Scientists are not sure how much it will slow down. Some say it is a long-term change. Others say it is just natural. New studies give better numbers. An old study said the AMOC could slow by 30% by 2100. A new study says it could slow by 50%. Scientists say this new study is more certain. They say the risk is real. One scientist said the chance of big problems is now higher. If the AMOC slows down a lot, there will be changes. Winters in parts of Europe could be very cold, maybe -20°C. Summers will stay warm. Sea levels on the east coast of Canada could rise by about 25 centimetres. There could be more bad weather for farming. For example, warm spring then frost can kill plants. The tropical rain belt could move south. Sea levels around the world could rise by one metre. People may need to move to warmer places or away from coasts.

Conclusion

The AMOC is getting weaker because of climate change. It will not stop soon, but it will slow down. This will change temperatures, sea levels, and farming in many places. Scientists say we need to watch the AMOC and tell people about the risks. The effects will be important for future generations.

Vocabulary Learning

climate (n.)
usual weather in a place氣候
Example:Climate change is causing problems.
cold (adj.)
having low temperature寒冷的
Example:Winters in parts of Europe could be very cold.
current (n.)
flow of water in the ocean or river水流；洋流
Example:The ocean current moves warm water to the north.
slow (v.)
to move or happen at a low speed減慢；變慢
Example:The current may slow down a lot.
warm (adj.)
having a little heat溫暖的
Example:Warm water helps keep Europe warm.

Sentence Learning

Scientists now think the AMOC may slow down a lot by the year 2100.
Time Marker: 'now' and 'by the year 2100' show when the action happens. 'now' means at this time. 'by the year 2100' means before or at that future time.時間標記：「now」和「by the year 2100」表示動作發生的時間。「now」意指現在。「by the year 2100」意指在2100年之前或當時。
But they do not think it will stop completely.
Contrast Connector: 'But' connects two opposite ideas. The first idea is that the current may slow down; the second is that it will not stop. 'But' shows contrast.對比連接詞：「But」連接兩個相反的想法。第一個想法是洋流可能會減慢；第二個是它不會完全停止。「But」表示對比。
Ice from Greenland melts and adds fresh water to the ocean.
Addition Connector: 'And' connects two actions: ice melts and adds water. It shows that both happen. Also, 'from Greenland' is a prepositional phrase showing origin, and 'to the ocean' shows direction.附加連接詞：「And」連接兩個動作：冰融化並增加淡水。它表示兩者都發生。另外，「from Greenland」是表示來源的介詞短語，「to the ocean」表示方向。
When the water is less salty, it does not sink as much.
Time Connector: 'When' introduces a condition or time. It means at the time the water is less salty, the sinking decreases.時間連接詞：「When」引入一個條件或時間。意指當海水鹽度較低時，下沉的程度減少。
If the AMOC slows down a lot, there will be changes.
Condition Connector: 'If' introduces a condition. It means if the AMOC slows down a lot, then changes will happen.條件連接詞：「If」引入一個條件。意指如果AMOC大幅減慢，那麼將會發生變化。