Most people consider climate change a serious issue, but rank other problems as more important. That affects climate policy


Shutterstock/riekephotos

Sam Crawley, Te Herenga Waka — Victoria University of WellingtonStraight denial of climate change is now relatively rare. Most people believe it is happening and is a serious problem. But many rank other issues — healthcare and the economy — as more important.

This means people can’t be easily classified as either deniers or believers when it comes to climate change. In my research, I focused on understanding the complexity of climate opinion in light of the slow political response to climate change around the world.

I conducted an online survey in the UK and found 78% of respondents were extremely or fairly certain climate change is happening.

But when asked to rank eight issues (climate change, healthcare, education, crime, immigration, economy, terrorism and poverty) from most to least important to the country, 38% ranked climate change as least important, with a further 15% placing it seventh out of eight.

Recent pledges from a number of large countries to reach net zero in greenhouse gas emissions by 2050 have led Climate Action Tracker to project that limiting warming to 2℃ by 2100 may be possible.

Although this progress is heartening, it has taken many years to reach this point and the challenges in actually meeting these emission targets cannot be overstated.

Climate ranking in other countries

I found similar results in other countries. Based on a Eurobarometer survey of 27,901 European Union citizens, a majority of the populations in all EU member countries are concerned about climate change, but only 43% across the EU rank it in the top four most important issues for the world. There are some differences between countries — climate change tends to be ranked higher in Nordic countries and lower in Eastern Europe.

Fewer than 5% of 3,445 respondents in the 2017 New Zealand Election Study said the environment was the most important election issue and an even smaller number specifically mentioned climate change.




Read more:
NZ election 2020: survey shows voters are divided on climate policy and urgency of action


Why are some people more engaged with climate change than others? People’s worldview or ideology seem to be particularly important.

In many countries — including, as illustrated in my research, the UK and New Zealand — there are partisan and political divides in climate change with supporters of right-wing parties less likely to support climate change policies or to see it as an important issue.

People who support free-market economics, hold authoritarian attitudes or have exclusionary attitudes towards minorities are also less likely to engage with climate change.

Consequences for climate policy

In democracies, politicians often respond to public opinion; ignoring it risks being voted out at the next election. But the degree to which they do so depends on how important the issue is to the public relative to other issues.

If people are not thinking about an issue when they go to vote, politicians are less likely to give that issue much attention. As my research shows, people in most countries don’t give climate change a high importance ranking, and politicians are therefore not under enough public pressure to take the difficult steps required to combat climate change.

There are other reasons for the slow political response to climate change, besides the low importance of climate change among the public. Vested interests, such as fossil fuel companies, are undoubtedly involved in slowing the adoption of strong climate policies in many countries.




Read more:
Climate explained: Why are climate change skeptics often right-wing conservatives?


Although only a minority of the population, climate change deniers may also make some politicians hesitate to act. But, regardless of the influence of vested interests and deniers, it is difficult for politicians to act on climate change when the public believes other issues are more important.

Understanding the relationship between public opinion and climate policy can help focus the efforts of climate campaigners. Perhaps less attention could be paid to the influence of vested interests.

Given the deep ideological reasons climate change deniers have for their disbelief, it’s unlikely they will be convinced otherwise. Fortunately, this may not be required to move climate policy forward.

As my research reveals, the majority of the public want action on climate change but tend to be more concerned about other issues. Campaigners might find it useful to focus their attention on persuading this section of the population about the urgency of climate action.The Conversation

Sam Crawley, Researcher, Te Herenga Waka — Victoria University of Wellington

This article is republished from The Conversation under a Creative Commons license. Read the original article.

‘One sip can kill’: why a highly toxic herbicide should be banned in Australia


Shutterstock

Nedeljka Rosic, Southern Cross University; Joanne Bradbury, Southern Cross University, and Sandra Grace, Southern Cross UniversityThere’s a weedkiller used in Australia that’s so toxic, one sip could kill you. It’s called paraquat and debate is brewing over whether it should be banned.

Paraquat is already outlawed in many places around the world. The Australian Pesticides and Veterinary Medicines Authority has been reviewing paraquat’s use here for more than two decades, and its final decision is due later this year.

We are medical and environmental scientists, and have researched the harmful effects of paraquat, even when it’s used within the recommended safety range. We strongly believe the highly toxic chemical should be banned in Australia.

The potentially lethal effects on humans are well known. In Australia in 2012, for example, a farmer died after a herbicide containing paraquat accidentally sprayed into his mouth. And our research has found paraquat also causes serious environmental damage.

Brown dead plants
Paraquat is used to spray crops, but can harm humans and wildlife.
Shutterstock

Paraquat: the story so far

Paraquat is the active ingredient in Gramoxone, among other products. It has been used since the 1950s, mostly to control grass and weeds around crops such as rice, cotton and soybeans.

Paraquat is registered as a schedule 7 poison on the national registration scheme, meaning its use is strictly regulated.

Suppliers of paraquat say it should not be banned, insisting herbicides containing it are safe for people and the environment when used for their intended purpose and according to label instructions.

Farmers have also argued against a ban, saying it would force them to use more expensive, less effective alternatives and reduce crop yield.

Paraquat has been banned in more than 50 countries, including the United Kingdom, China, Thailand and European Union nations. However, it’s still widely used by farmers in the developing world, and in Australia and the United States.




Read more:
Ban on toxic mercury looms in sugar cane farming, but Australia still has a way to go


Paraquat bottles with Thai language label
Paraquat is now banned in Thailand, among other nations.
Shutterstock

A chemical peril

Paraquat is a non-selective herbicide, which means it kills plants indiscriminately. It does so by inhibiting photosynthesis, the process by which plants convert sunlight into chemical energy.

Paraquat stays in the environment for a long time. It’s well known for causing collateral damage to plants and animals. For example, even at very low concentrations, paraquat has been found to harm the growth of honey bee eggs.

Exposure to living organisms can occur by spray drift or when paraquat is sprayed on crops then reaches surface and underground sources of drinking water.

Paraquat can have unintended consequences for biological organisms and the environment, particular in waterways. Our recent paper summarised the evidence of the harmful effects of paraquat at realistic field concentrations.

We found evidence that paraquat can severely inhibit healthy bacterial growth in aquatic environments, which in turn affects nutrient cycling and the decomposition of organic matter.

The research also shows paraquat can distort tropical freshwater plankton communities by negatively impacting metabolic diversity and reducing phytoplankton growth.

In fish, paraquat has been found to lead to a death rate of common carp three times higher than the weed it is used to control.

Common carp in the wild
Research shows paraquat kills common carp at a higher rate than the weed it’s meant to control.
Shutterstock

‘One sip can kill’

In addition to the environmental effects, of course, paraquat is highly toxic to humans. A small accidental sip can be fatal and there is no antidote.

The US Centers for Disease Control and Prevention says paraquat is a leading cause of fatal poisoning in parts of Asia, the Pacific Islands, and South and Central Americas.

Paraquat enters the body through the skin, digestive system or lungs. If ingested in sufficient amounts, it causes lung damage, leading to pulmonary fibrosis and death through respiratory failure. The liver and kidney can also fail.

Several recent incidents in Australia demonstrate the risks of paraquat poisoning due to human error, even within the current strict regulations.

According to news reports, the Queensland farmer poisoned by paraquat in 2012 was filling a pressure pump to control weeds on his property. The unit cracked and paraquat sprayed over his body and face, entering his mouth.

In 2017, an adult with autism took a sip from a Coke bottle used to store paraquat. The bottle had been left in a disabled toilet at a sports ground in New South Wales. The man was initially given 12 hours to live, but fortunately recovered after two weeks in hospital.




Read more:
Pesticides and suicide prevention – why research needs to be put into practice


chemical being poured into pressure pump container
A Queensland farmer died in 2012 after paraquat accidentally sprayed in his face when he filled a pressure pump.
Shutterstock

Paraquat: not worth the risk

There’s a growing awareness of the threats posed by global chemical use. In fact, a paper released this week suggests the potential risk to humanity is on a scale equivalent to climate change.

Paraquat is no doubt an effective herbicide. However, in our view, the risks it poses to humans and the environment outweigh the agricultural benefits.

Current regulation in Australia has not prevented harm from paraquat. It’s time for Australia to join the movement towards a global ban on this toxic chemical.




Read more:
The real cost of pesticides in Australia’s food boom



Editor’s note: the article has been updated to reflect the fact products other than Gramoxone also contain paraquat.The Conversation

Nedeljka Rosic, Senior Lecturer, Southern Cross University; Joanne Bradbury, Senior Lecturer, Evidence Based Healthcare, Faculty of Health, Southern Cross University, and Sandra Grace, Professor, Southern Cross University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

We found a secret history of megadroughts written in tree rings. The wheatbelt’s future may be drier than we thought


An almost-dry dam, surrounded by wheat fields, in WA’s wheatbelt region.
Shutterstock

Alison O’Donnell, The University of Western Australia; Edward Cook, Columbia University, and Pauline Grierson, The University of Western AustraliaDrought over the last two decades has dealt a heavy blow to the wheatbelt of Western Australia, the country’s most productive grain-growing region. Since 2000, winter rainfall has plummeted by almost 20% and shifted grain-growing areas towards the coast.

Our recent research, however, found these dry conditions are nothing out of the ordinary for the region.

In fact, after analysing rings in centuries-old tree trunks, we found the region has seen far worse “megadroughts” over the last 700 years. Australia’s instrumental climate records only cover the last 120 or so years (at best), which means these historic droughts may not have previously been known to science.

Our research also found the 20th century was the wettest of the last seven centuries in the wheatbelt. This is important, because it means scientists have likely been underestimating the actual risk of drought – and this will be exacerbated by climate change.

What we can learn from ancient trees

We estimate the risk of extreme climate events, such as droughts, cyclones and floods, based on what we know from instrumental climate records from weather stations. Extending climate records by hundreds or even thousands of years means scientists would be able to get a much better understanding of climate variability and the risk of extreme events.

_Callitris_ trees overlooking a salt lake
Callitris trees overlooking a salt lake. We pulled a column of wood from these tree trunks to investigate past climate changes in the region.
Alison O’Donnell, Author provided

Thankfully we can do just that in many parts of the world using proxy records — things like tree rings, corals, stalagmites and ice cores in Antarctica. These record evidence of past climate conditions as they grow.

For example, trees typically create a new layer of growth (“growth ring”) around their trunks, just beneath the bark, each year. The amount of growth generally depends on how much rain falls in the year. The more it rains, the more growth and the wider the ring.

Tree rings of Callitris columellaris.
Alison O’Donnell, Author provided

We used growth rings of native cypress trees (Callitris columellaris) near a large salt lake at the eastern edge the wheatbelt region. These trees can live for up to 1,000 years, perhaps even longer.

We can examine the growth rings of living trees without cutting them down by carefully drilling a small hole into the trunk and extracting a column (“core”) of wood about the size of a drinking straw. By measuring the ring widths, we developed a timeline of tree growth and used this to work out how much rain fell in each year of a tree’s life.

This method allowed us to reconstruct the last 668 years of autumn-winter rainfall in the wheatbelt.

A tree trunk with a blue scientific instrument attached
A tree borer – a hollow drill used to extract ‘cores’ of wood from tree trunks.
Alison O’Donnell, Author provided

A history of megadroughts

One of the most pressing questions for the wheatbelt is whether the decline in autumn-winter rainfall observed in recent decades is unusual or extreme. Our extended record of rainfall lets us answer this question.

Yes, rainfall since 2000 was below the 668-year average — but it was not extremely low.

The last two decades may seem particularly bad because our expectations of rainfall in the wheatbelt are likely based on memories of higher rainfall. But this frequent wet weather has actually been the anomaly. Our tree rings revealed the 20th century was wetter than any other in the last 700 years, with 12% more rain in the autumn-winter seasons on average than the 19th century.




Read more:
500 years of drought and flood: trees and corals reveal Australia’s climate history


Before the 20th century, the wheatbelt saw five droughts that were longer and more severe than any we’ve experienced in living memory, or have recorded in instrumental records. This includes two dry periods in the late 18th and 19th centuries that persisted for more than 30 years, making them “megadroughts”.

While the most recent dry period has persisted for almost two decades so far, rainfall during this period is at least 10% higher than it was in the two historical megadroughts.

This suggests prolonged droughts are a natural and relatively common feature of the wheatbelt’s climate.

An aerial view of the tree-ring site, home to trees that can live up to 1,000 years.
Hannah Etchells, Author provided

So how does human-caused climate change play into this?

It’s likely both natural climate variability and human-caused climate change contributed to the wheatbelt’s recent decline in rainfall. Unfortunately, it’s also likely their combined influence will lead to even less rainfall in the near future.

What happens now?

Our findings have important implications for assessing the risk of drought. It’s now clear we need to look beyond these instrumental records to more accurately estimate the risk of droughts for the wheatbelt.

But currently, proxy climate records like tree rings aren’t generally used in drought risk models, as there aren’t many of them in the regions scientists want to research.

Improving risk estimates leads to better informed decisions around preparing for and managing the effects of droughts and future natural disasters.




Read more:
To help drought-affected farmers, we need to support them in good times as well as bad


Our findings are a confronting prospect for the future of farming in the wheatbelt.

Australian farmers have shown tremendous innovation in their ability to adapt in the face of drought, with many shifting from livestock to crops. This resilience will be critical as farmers face a drier, more difficult future.The Conversation

Alison O’Donnell, Research Fellow in Dendroclimatology, The University of Western Australia; Edward Cook, Ewing Lamont Research Professor, Director Of Tree-Ring Lab, Columbia University, and Pauline Grierson, Director, West Australian Biogeochemistry Centre, The University of Western Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.