forecast是什么意思？

In the past, falling oil prices have given a boost to the world economy, but recent forecasts for global growth have been toned down, even as oil prices sink lower and lower.

This prompted the company to cut its forecasts for the full fourth quarter.

All the forecasts, plans, and anticipations cited above have failed so miserably because their authors and promoters thought the transitions they hoped to implement would proceed unlike all previous energy transitions, and that their progress could be accelerated in an unprecedented manner.

Yet until recently the worst forecasts were almost exclusively linked to direct human activity, such as clear-cutting and burning for pastures or farms.

I am responsible for financial development programs in many parts of the world, so forecasting long range trends and making predictions on the basis of present evidence is what I do.

In the 1990s, many economists began to look at chaos theory as a way of providing models for forecasting

Doesn't that mean that forecasting is impossible?