It is harder than experts thought to predict when sudden shifts in earth’s natural systems will occur, a new study has claimed.

Researchers at University of California, Davis, said many scientists are looking for the warning signs that herald sudden changes in natural systems, in hopes of forestalling those changes or improving our preparations for them but unfortunately that regime shifts can happen without warning.

“It is harder than thought to predict when sudden shifts in earth’s natural systems will occur. Our new study found, unfortunately, that regime shifts with potentially large consequences can happen without warning — systems can tip precipitously,” senior author Alan Hastings said.

Mr. Hastings said, “This means that some effects of global climate change on ecosystems can be seen only once the effects are dramatic. By that point returning the system to a desirable state will be difficult, if not impossible.”

The current study focuses on models from ecology, but its findings may be applicable to other complex systems, especially ones involving human dynamics such as harvesting of fish stocks or financial markets.

The team led by Mr. Hastings, one of the world’s top experts, is using mathematical models (sets of equations) to understand natural systems, the Science Daily reported.

Scientists widely agree that global climate change is already causing major environmental effects, such as droughts, heat waves and rising sea level and they fear that worse is in store.