Explanation:

Only statements 2&3 are correct.

• A recent scientific study estimates a timescale for the collapse of the Gulf Stream between 2025 and 2095, with a central estimate of 2050, if global carbon emissions are not reduced. 

About Gulf Stream

• It is a swift and warm ocean current that flows along the eastern coast of North America and crosses the Atlantic Ocean towards Europe.

• This extension towards Europe is known as the North Atlantic drift.

• The Gulf Stream transports an amount of water greater than that carried by all of the world's rivers combined.

Key characteristics

• Location: It originates in the Gulf of Mexico.  It then travels northward along the eastern coast of the United States. It follows a north-eastward path across the western North Atlantic Ocean.

• Sources: The two equatorial sources of the Gulf Stream are the North Equatorial Current (NEC), which flows generally westward along the Tropic of Cancer, and the South Equatorial Current (SEC), which flows westward from southwestern Africa to South America and then northward to the Caribbean Sea. Together, these two warm currents, along with waters from the Gulf of Mexico, form the Gulf Stream.

• Warmth: The current carries warm water from the tropics (around 25 to 28°C or 77 to 82°F) to higher latitudes.

• Width and Speed: The Gulf Stream is several hundred kilometres wide and can flow at an average speed of about four miles per hour (6.4 kilometers per hour). However, its speed can vary depending on the location and other factors.

• Depth: The current is also very deep, extending to depths of up to 1,000 meters.

• Climate Regulation: It moderates the temperatures along the eastern coast of North America, keeping the coastal areas warmer in winter and cooler in summer compared to inland regions at the same latitudes. Since the Gulf Stream also extends toward Europe, it warms Western European countries as well.

Hence option 2nd is correct.