Keep up with the latest in environmental issues

Food transport emissions

University of Sydney researchers have conducted an analysis incorporating 74 countries and looking at transport distances feeding into sectors including vegetables and fruit, livestock, coal and manufacturing. They found that global food systems contribute about 30 per cent of total human-produced greenhouse gas emissions. Of that, food transport contributes 19 per cent (three gigatonnes of emissions annually) and food transport emissions add up to nearly half of all emissions from road vehicles. Transport emissions for fruit and vegetables contribute over a third because these commodities require refrigeration while being transported. Analysis showed Australia to be the world’s second-largest exporter of food transport emissions because of its widely dispersed primary production. The researchers say that eating seasonal, locally generated food is the answer, even if that means creating peri-urban agriculture to feed city dwellers. Eating locally would reduce annual global emissions by 0.38 gigatonnes (in perspective, a gigatonne equals the mass of all land animals in the world, excluding humans).

Source: Nature Food

Cats and catnip

If you have ever seen a cat with a bit of catnip (Nepeta cataria) you will know they go crazy for it. The theory has been that catnip, and its Asian relative silvervine, have intoxicant properties; now a new study shows there might be more to it than that. Researchers have found that catnip and silvervine leaves contain iridoid compounds called nepetalactol and nepetalactone. These iridoids function to the protect the plants from pests, and the researchers found that when cats physically damaged the plants by rolling on or chewing them the release of these compounds increased 10-fold. Additionally, the iridoids changed structure when released from damaged leaves by cats rolling, licking and chewing. The altered iridoids were even more repellent to mosquitoes than the original compounds. Smelling the altered iridoids also stimulated the cats to chew and lick more. In essence, catnip is a self-regenerating insect repellent for cats.

Source: iScience

Climate coverage changes minds

For a new study, researchers had almost 3000 subjects take part in four stages. Stage one involved subjects reading online authentic articles reflecting the scientific consensus on climate change (it is happening, and we need to address it now). In the second and third stages they read either another scientific article, an opinion piece that was sceptical of climate science, an article that discussed the debate over climate science or an unrelated article. In the fourth stage subjects were asked their beliefs about the science of climate change and what they thought should be done. After stage one, people, including some who originally rejected climate change, were convinced by scientific reporting that climate change is a pressing issue and that governments should do more about it. This effect largely disappeared in later stages of the study, especially after reading climate sceptic opinions. Still, it means that the science can change minds; we just need to keep reporting it.

Source: Proceedings of the National Academy of Sciences

Unlimited want

A fundamental economic principle of capitalism is that everyone is motivated by “unlimited wants” and will strive to accumulate as much wealth as they can. Hence the belief in, and need for, perpetual economic growth. In a new study, researchers surveyed 8000 people across 33 countries about their “absolutely ideal life”. They found that in 86 per cent of countries people felt they could achieve this with as little as $1 million. This might sound a lot, but remember that is across their whole life. The researchers point out that this finding reveals that people’s wants are actually quite moderate. The ideology of unlimited want sees people as voracious consumers and creates social pressure for people to buy more than they want. If policy setters see people as more moderate and reasonable it can become socially easier for people to behave in ways that genuinely make them happy and support a stronger, more sustainable society.

Source: Nature Sustainability