We may be just a few years away from a global climate prediction model. Periodic ice age and drought have played the earth for 5 million years.

Our results confirm that early warning signals can, in principle, be seen before a climate tipping point is reached.

Good news for people that need this information to plan for climate disasters like our current drought that rivals Dust Bowl conditions.

We address whether robust early warning signals can, in principle, be provided before a climate tipping point is reached, focusing on methods that seek to detect critical slowing down as a precursor of bifurcation.

There are two competing designs for the model.

The ACF method is simpler, faster to calculate and more intuitive, but the indicator is bounded by an upper limit and therefore loses sensitivity near critical behaviour. The DFA indicator is more sensitive, providing extra information about the dynamics near critical behaviour, but is more data-demanding, oscillating when using short time series, thus making it less applicable to them.