"Rain bomb." 

Those were the words used to describe the weather that hit Brisbane on Sunday. Four inches of rain tumbled from the sky, causing flash floods. Roads were cut; 2,145 homes and 2,356 businesses were left underwater. Almost 1,000 schools were unable to open yesterday.   

Queensland's head of emergency services, Carlene York, asked people to "stay off the roads unless you desperately have to be on them."

 Brisbane also suffered terrible floods in 2011. At the time they were called a "once in a century event". We now know that they were not.

Yesterday the Intergovernmental Panel on Climate Change (IPCC) published its latest report. It was deeply worrying.

The report warned that global warming could reach 1.5C above pre-industrial levels within 20 years.

At that point up to 14% of species living on land would face extinction. Those that live on coasts or by rivers are most at risk because of rises in sea level and droughts.

Other dangers include heatwaves, the spread of disease and a fall in food production.

The report looks at whether people can adapt to meet these problems. The UN aims to make at least 30% of the world into conservation areas.

The report recommends developing early-warning systems and building seawalls and river barriers. And it emphasises "nature-based" solutions: in other words, using the power of nature to combat global warming.

Tree-planting is an obvious example. As well as absorbing CO2, trees help protect land from flooding. Mangrove swamps act as natural seawalls, while peat bogs absorb excess water.

Developing these natural defences could cost half as much as building artificial ones.

Nature-based solutions also create local jobs, help fight pollution and restore wildlife habitats.

Yes: Natural forces always find a way of balancing themselves. Human interference only makes things worse.

No: Trying to harness nature is a waste of time. We need drastic solutions. They can only be provided by human science.

Or... Only by accelerating natural processes with the help of technology can we solve the problem quickly enough to survive.