Climate changes multiplying hazards, and the limits to ‘top down’ solutions

Mind-blowing’: Hazards to multiply and accumulate with climate change, https://www.brisbanetimes.com.au/environment/climate-change/mind-blowing-hazards-to-multiply-and-accumulate-with-climate-change-20181119-p50gx7.html, By Peter Hannam

20 November 2018 — Humanity is already enduring cumulative effects from climate change and damages will continue to mount along with carbon emissions, a new study has found. Tropical coastal regions will be the most exposed to multiple hazards.

The research – which involved analysis of 3280 research papers and was published on Tuesday by Nature Climate Change – identified 467 pathways that populations were already being hit by a warmer climate. Those impacts will likely increase and intensify unless aggressive efforts are taken to curb greenhouse gas pollution.

“We never stopped being surprised by how many impacts had already happened to us,” said Camilo Mora, an associate professor at the University of Hawaii and lead author of the paper. (An interactive can be seen here.)

“It was also mind-blowing that we just refuse to wake up about how serious this is,” he said.

Examples of impacts cited ranged from famine deaths triggered by droughts and the increased spread of diseases in a warming world, to worsening heavy metal contamination in lakes after wild fires and a poor Russian wheat harvest amid heatwaves in 2010 that led to a doubling of world prices for the commodity.

The tendency towards more extreme weather includes accelerated evaporation rates as temperatures rise, worsening droughts and contributing to more severe wildfires – a combination currently being played out in California, Professor Mora said.

Similarly, with the atmosphere holding about 7 per cent more moisture for each degree of warming, the potential for more intense rain events increases.

About 20-40 per cent of the rainfall from the record wet Hurricane Harvey that soaked Houston in 2017 has been attributed to climate change, Professor Mora said.

Coastal regions were already being exposed to overlapping hazards from both the land and the ocean, making them particularly vulnerable locations now and in the future.

If carbon emissions continued to rise unabated at their current rate, tropical coastal areas such as in Southeast Asia could face as many as six climate hazards concurrently, the paper said.

These included rising sea level and the increased acidity of oceans as they absorb more carbon from the atmosphere.

Top-down limitations

While societies often relied on top-down approaches to dealing with emissions, the result was often a fragile policy set-up.

“One person can come along and reverse the whole thing,” Professor Mora said.

“We need to build the solution for climate change from the bottom up,” he said, citing a project currently being tested in Hawaii to make the US state fully carbon neutral by tree planting and other efforts.