Synthesising everything we know about climate change – expert reaction

Not only are there feasible ways to cut down greenhouse gas emissions and adapt to human-caused climate change, but these actions can be taken right now, according to a major scientific report released today.

The Intergovernmental Panel on Climate Change (IPCC) has released its Synthesis Report for the Sixth Assessment Cycle, bringing together comprehensive, previously released reports on the physical science of climate change, what can be done to adapt to it, and what can be done to reduce the amount of greenhouse gases we emit.

The Science Media Centre asked experts to comment on the report. Here are their responses –

• Dr Daniel Kingston, Senior Lecturer, University of Otago:

“This synthesis report provides a summary of the three major IPCC assessments released in 2021 and 2022, plus three further special reports. It is important to note that these reports provide a summary of current understanding, rather than primary research undertaken by the IPCC itself. Some of the leading experts in the world volunteer their time to write these reports. An open review process then takes place allowing other experts to scrutinise the reports prior to publication. Finally, the synthesis report is reviewed line-by-line by member governments from all over the world, plus scientific experts, prior to release.

“One of the key headlines from this synthesis is that human activities have unequivocally caused global surface temperatures to rise. The use of the term ‘unequivocally’ is hugely meaningful here. Scientists are typically cautious and like to include many ‘ifs’ and ‘buts’ with their statements. To eliminate all doubt that humans are causing global warming highlights starkly just how overwhelming the evidence is in this case.

Experts discuss climate warming and the fuelling of Cyclone Gabrielle

Significant parts of the country today have been dealing with the devastation caused during a night of extreme weather which left communities cut off across the North Island.

The Minister for Emergency Management, Kieran McAnulty, declared a national state of emergency at 8.43am. It was only the third time a New Zealand Government had declared a national state of emergency.

Previous declarations were triggered by the Christchurch earthquakes and Covid-19 pandemic.

The declaration initially applied to the six regions that had declared a local state of emergency: Northland, Auckland, Tairāwhiti, Bay of Plenty, Waikato, and Hawke’s Bay. It was subsequently extended to include the Tararua District, which declared a local state of emergency shortly after Mr McAnulty declared a national emergency.

Waikato graduate is developing methodology for predicting climate change events

A University of Waikato alumna hopes her research on flood forecasting and hydrometeorology will help to better predict weather events.

Elise Legarth, who graduated from the University in 2018 with a Bachelor of Science (BSc), majoring in Earth Sciences and Agribusiness,  is now one year into her PhD in Atmospheric Science and Meteorology at The University of British Columbia in Canada.

She received Canada’s top and most prestigious scholarship, the Vanier Scholarship, which she put towards her research topic: the development of an improved methodology for estimating probable maximum precipitation and probable maximum flood.

Her aim is to help society, in particular the agricultural industry, adapt to climate change.

Climate change the issue on which Australians do not want both sides of the argument: new research

Researchers have found Australians do not want both sides of the argument when climate change is at issue. They also found (encouragingly) that the most popular sources of climate change news are scientists, experts and academics (50%).  The findings are reported today in The Conversation in an article by Sora Park, Associate Dean of Research in the Faculty of Arts & Design, Kerry McCallum, Professor of Communication and Media Studies, Director, News and Media Research Centre, and Kieran McGuinness post-doctoral felllow, News & Media Research Centre, at the University of Canberra  They write:

Should journalists always treat an issue even-handedly? Our research reveals that when it comes to climate change, many Australians would prefer they didn’t. For general news, people want news outlets to reflect a range of views so they can make up their own mind about an issue. However, when it comes to news about climate change, four in ten say news outlets should pick a side.

There is a divide driven by political orientation on how people think news outlets should be reporting on climate change. More than half (51%) of those who identify as left-wing and 42% of those who identify as centre of politics say news outlets should take a clear position. In contrast, only 24% of right-leaning audiences say so.

Relocating farmland could turn back clock 20 years on carbon emissions, scientists say

Scientists have produced a map showing where the world’s major food crops should be grown to maximise yield and minimise environmental impact. This would capture large amounts of carbon, increase biodiversity, and cut agricultural use of freshwater to zero.

The reimagined world map of agriculture includes large new farming areas for many major crops around the cornbelt in the mid-western US, and below the Sahara desert. Huge areas of farmland in Europe and India would be restored to natural habitat.

The redesign — assuming high-input, mechanised farming — would cut the carbon impact of global croplands by 71%, by allowing land to revert to its natural, forested state. This is the equivalent of capturing twenty years’ worth of our current net CO₂ emissions. Trees capture carbon as they grow, and also enable more carbon to be captured by the soil than when crops are grown in it.

Climate change: a threat to human wellbeing and health of the planet

Human-induced climate change is causing dangerous and widespread disruption in nature and affecting the lives of billions of people around the world, despite efforts to reduce the risks.

People and ecosystems least able to cope are being hardest hit, said scientists in the latest Intergovernmental Panel on Climate Change (IPCC) report, released this week.

“This report is a dire warning about the consequences of inaction,” said Hoesung Lee, Chair of the IPCC.

“It shows that climate change is a grave and mounting threat to our wellbeing and a healthy planet. Our actions today will shape how people adapt and nature responds to increasing climate risks.”

The world faces unavoidable multiple climate hazards over the next two decades with global warming of 1.5°C (2.7°F). Even temporarily exceeding this warming level will result in additional severe impacts, some of which will be irreversible.

IPCC begins process to approve report on impacts of climate change

The Intergovernmental Panel on Climate Change (IPCC) has opened the virtual meeting to approve the Working Group II report: Climate Change 2022: Impacts, Adaptation and Vulnerability.

The report, which focuses on impacts, adaptation and vulnerability to climate change, includes a chapter specifically on Australia and New Zealand.

The session began on 14 February and the final report is expected on 28 February.

The report, a second instalment of the Sixth Assessment Report, integrates more strongly natural, social and economic sciences, highlighting the role of social justice and diverse forms of knowledge such as indigenous and local knowledge. It also reflects the increasing importance of urgent and immediate action to address climate risks.

It brings more knowledge at local and regional levels and linkages between biodiversity and climate change.

The report prepared by IPCC’s Working Group II will build on the Working Group I contribution to the Sixth Assessment Report released in August 2021 that showed climate change is widespread, rapid and intensifying.

Key crops face major shifts in response to global warming

The BBC has reported the results of a new study which finds the parts of the world suitable for growing coffee, cashews and avocados will change dramatically as the world heats up.

On the other hand, New Zealand is among the countries where growing areas will become more suitable for coffee.

The research has been published in the journal Plos One.

Key coffee regions in Brazil, Indonesia, Vietnam and Colombia will all “drastically decrease” by around 50 per cent by 2050.

Suitable areas for cashews and avocados will increase but most will be far from current sites of production.

The authors say that greater efforts must be made to help farmers adapt.

Rain, rain go away, researchers find you are bad for the economy

Increases in the number of wet days which a region experiences may lead to a reduction in economic growth, a new global study suggests.

Leonie Wenz and colleagues combined data on daily rainfall with subnational economic output for 1,544 regions across 77 countries over the past 40 years to model the impact of rainfall change on economic growth.

They found that an increase in the number of wet days or extreme daily rainfall — the annual total of rain on days that exceed the 99.9th percentile of the distribution of daily rainfall between 1979–2019 — leads to a reduction in economic growth.

In Australia, the study showed the Northern Territory and the whole of the east coast had historically shown the greatest drop in economic growth rates when the number of wet days was higher.

Rich countries appeared more sensitive to daily rainfall which the authors say may be due to their smaller dependence on agriculture and greater dependence on services.

The findings highlight the potential negative impact that human-induced climate change could have on the global economy.

Changes in the Earth’s hydrological cycle are anticipated as a result of anthropogenic climate change.

Water availability affects agricultural productivity, labour outcomes and conflict, and flash flooding can cause damage and impact economic output.

But rainfall changes are difficult to model or are assessed on a single country basis, making it difficult to estimate the global economic cost of rainfall induced by climate change.

The researchers suggest that higher-income nations and the service and manufacturing sectors are most strongly hindered by increases in daily rainfall.

Their analysis also indicates that droughts that differ from historical monthly means may lead to economic losses.

They argue that their findings demonstrate that our previous understanding of the economic effects of rainfall changes was incomplete. They conclude that further research is needed to quantify the impacts of future changes in rainfall on economic growth.

• Link to research (DOI):1038/s41586-021-04283-8

Source:  Scimex

High-tech investment extends drought forecasting for farmers and growers

The Government is investing in the development of a new forecasting tool that makes full use of innovative climate modelling to help farmers and growers prepare for dry conditions.

The new approach will cost $200,000, jointly funded through the Ministry for Primary Industries (MPI) and National Institute of Water and Atmospheric Research (NIWA).

It will provide daily drought forecasts out to 35 days. Later, the project will also explore drought predictions up to six months ahead. NIWA currently provides seasonal climate outlooks each month that look three months ahead, but are not drought specific.

“We are harnessing the latest in climate and data science to put information into the hands of the people who can make the best use of it,” Agriculture Minister Damien O’Connor said.

“Knowing well in advance when dry conditions are heading your way means you can cut your cloth accordingly at critical times on-farm. Having early warning can help determine stocking levels, water storage and feed management options.”