SYDNEY, April 1 -- A new study from the University of New South Wales (UNSW) has warned that global GDP could plummet by 40% by 2100 if temperatures rise by 4 degrees Celsius-far worse than earlier estimates of an 11% decline.

The research, conducted by UNSW's Institute for Climate Risk & Response (ICRR), challenges existing economic models that have guided climate policies, highlighting the need for urgent action.

Lead researcher Timothy Neal explained that past models underestimated climate impacts by ignoring how extreme weather disrupts global supply chains. Earlier assessments relied on historical weather-economy links without considering today's interconnected economies.

"Previous models mistakenly suggested severe climate change...