Andrew Pam

2025-03-07 03:01:05

Weakening currents in the Atlantic may mean a wetter northern Australia and drier New Zealand

Europe is warmed by heat from ocean currents, which move water from the warm tropics to the colder North Atlantic. Once the warm, salty water from the tropics reach the polar region, they cool enough to sink to the depths and flow back towards the Southern Ocean.

This enormous system of currents is known as the Atlantic Meridional Overturning Circulation (AMOC). Climate scientists are increasingly worried about the AMOC, which appears to be slowing down.

While there’s still debate over whether the AMOC has weakened over the last decades, climate models consistently show the AMOC will significantly weaken over the coming century due to the increase in heat-trapping atmospheric greenhouse gases. As more heat stays in the system, the ocean heats up and ice melts, adding fresh water to polar oceans. The overall effect is to slow these currents. The AMOC could weaken 30% by 2060.

A weaker AMOC would mean big changes in Europe, which benefits directly from the warmer waters it brings. But it would also change the climate in the Southern Hemisphere. Our new research shows a weakening of the AMOC would lead to a large change in rainfall patterns, leading to wetter summers in northern Australia and a drier New Zealand year-round. Indonesia and northern Papua New Guinea would also become drier.

Weakening currents in the Atlantic may mean a wetter northern Australia and drier New Zealand

Scientists are increasingly worried about a potential slowdown of the major Atlantic ocean current. Now we know it would affect the Southern Hemisphere

^{The Conversation}

Andrew Pam

2025-03-07 03:03:31

Solar developer unveils plan for “world’s deepest” undersea cable to link Australia and NZ grids

The founders of New Zealand solar developer Far North Solar Farm have announced an ambitious plan to build a 2-3GW high-voltage direct current (HVDC) subsea cable between New Zealand and Australia.

Designed to facilitate the trade of electricity between the two countries, the 2-3GW HVDC submarine cable would extend 2,600km across the Tasman Sea and help to increase generation and transmission capacity in both markets.

It would also support the increase of wholesale supply and retail competition, and accelerate the development of renewable energy in the two countries.

Taslink is the brainchild Australia’s John Telfer and New Zealand’s Richard Homewood, who founded Far North Solar farm in 2019.

Expected to cost upwards of $10 billion, the subsea cable would link the two countries from a point south of Auckland in the north of New Zealand’s North Island, to Newcastle on the New South Wales central coast.

The cable would be both the deepest and longest of its kind in the world and would be able to take advantage of the two countries’ close geographic and temporal proximity.

“The thing about New Zealand and Australia is that we have a two hour time difference, so we have a morning peak followed [two hours later] by Australia’s morning peak,” Richard Homewood told Radio New Zealand.

“We also have our peak demand in winter time (for heating), when we have cold and dry winters, whereas Australia has the highest demand on hot days in summer (for cooling).”

These sympathetic parallels would see Taslink buy power from one country at a cheaper rate and sell it to the other, and allow surplus Australian power to be traded to New Zealand when it’s needed, and vice versa.

“We will be purchasing power from the electricity markets in both countries, so we will have generators in New Zealand producing power that could be purchased by Taslink and sold into the Australian market,” Homewood continued.

“On the same way you could have generators in Australia… Say, solar, because Australia has an abundance of daytime solar.”

Solar developer unveils plan for "world's deepest" undersea cable to link Australia and NZ grids | RenewEconomy

Founders of a New Zealand solar developer announce ambitious plan to link Australia and New Zealand grid with a sub-sea cable.

^{Joshua S Hill (RenewEconomy)}