The long-feared "population bomb" may not go off, according to the authors of a new report that estimates that human numbers will peak lower and sooner than previously forecast, media reported.

The study, commissioned by the Club of Rome, projects that on current trends the world population will reach a high of 8.8 billion before the middle of the century, then decline rapidly. The peak could come earlier still if governments take progressive steps to raise average incomes and education levels.

The new forecasts are good news for the global environment. Once the demographic bulge is overcome, pressure on nature and the climate should start to ease, along with associated social and political tensions, The Guardian reported.

But the authors caution that falling birth rates alone will not solve the planet's environmental problems, which are already serious at the 8 billion level and are primarily caused by the excess consumption of a wealthy minority.

Declining populations can also create new problems, such as a shrinking workforce and greater stress on healthcare associated with an ageing society, as countries like Japan and South Korea are finding, The Guardian reported.

One of the authors of the report, Ben Callegari, said the findings were cause for optimism - but there was a catch. "This gives us evidence to believe the population bomb won't go off, but we still face significant challenges from an environmental perspective. We need a lot of effort to address the current development paradigm of overconsumption and overproduction, which are bigger problems than population."

Previous studies have painted a grimmer picture. Last year, the UN estimated the world population would hit 9.7 billion by the middle of the century and continue to rise for several decades afterwards, The Guardian reported.