Inequalities Fuel Human Impacts On Climate

Climate News Network - Tim Radford*

Scientists seek precision research tools to measure how human impacts and inequalities will feed back into future climate change.

Refugees forced from their homes by serious floods in Bihar state, northeast India. Image: Balazs Gardi via Flickr

For the second time this year, a group of climate scientists has called for a new approach to climate change research to produce a better and more precise idea of how the world will change as global average temperatures rise.
The call comes only weeks after a distinguished international team reminded researchers that some details of the planetary climate machine are still unresolved – such as what happens to all the carbon released by fossil fuel combustion, and how rainfall patterns will change in the decades to follow.
Neither group is challenging the general climate models, which broadly predict that, unless action is taken, global average temperatures could rise by 4°C and global sea levels by a metre or so. What each wants is more detailed answers.
The latest call comes from a team of US and Japanese scientists, who argue in their report in National Science Review journal that the human dimension is missing. What people do over the next decades will feed back into the mechanics of climate change.

Missing dimensions
The missing dimensions of the human impacts and contribution, they say, are threefold: the economic inequalities that stoke conflict and drive migration; the levels and patterns of consumption of resources that fuel these inequalities; and the numbers of people consuming these resources and demanding energy to improve their lives over the next two generations.
For instance, the scientists say, human choices make a difference. The rate of atmospheric concentrations of the greenhouse gases carbon dioxide, methane and nitrous oxide increased 700-fold, 1,000-fold and 300-fold respectively after the “green revolution” of the 1960s, compared with pre-industrial levels.
Population growth was a factor. So was economic growth. And this corresponded to a doubling of human impacts every 17 years.
“The doubling of this impact is shockingly rapid,” says the study leader, Safa Motesharri, a systems scientist at the University of Maryland’s National Socio-Environmental Synthesis Centre.

“These human impacts can only truly
be understood within the context
of economic inequality”

His co-author, Jorge Rivas, a researcher in environmental sustainability and political economy at the Institute for Global Environment and Society in Maryland, says: “These human impacts can only truly be understood within the context of economic inequality.
“The average per capita resource use in wealthy countries is five to 10 times higher than in developing countries, and the developed countries are responsible for over three-quarters of cumulative greenhouse gas emissions from 1850 to 2000.”
A third Maryland colleague, geographer Klaus Hubacek, says: “The disparity is even greater when inequality within countries is included. For example, about 50% of the world’s people live on less than $3 per day, 75% on less than $8.50, and 90% on less than $23.

Matter of urgency
“One effect of this inequality is that the top 10% produce almost as much total carbon emissions as the bottom 90% combined.”
So the researchers argue that, as a matter of urgency, climate modellers must try to make sense of the future by coupling their understanding of the Earth system – aspects such as temperature, evaporation, rainfall, forests, deserts, icecaps – with the human systems of agriculture, urban growth, investment, traffic, aid and trade.
“We cannot separate the issues of population growth, resource consumption, the burning of fossil fuels, and climate risk,” says Michael Mann, director of  the Earth System Science Centre at Penn State University, but who was not an author of the study.
“They are part of a coupled dynamical system, and, as the authors show, this has dire potential consequences for societal collapse. The implications couldn’t be more profound.” – Climate News Network

*Tim Radford, a founding editor of Climate News Network, worked for The Guardian for 32 years, for most of that time as science editor. He has been covering climate change since 1988.

Links

• It's More than Just Climate Change
• Call to unravel basic climate change
• Modeling sustainability: population, inequality, consumption, and bidirectional coupling of the Earth and Human Systems
• China trumps US on climate change
• Battery power boost to renewables
• Solar energy powers sustainable solutions

As Global Food Demand Rises, Climate Change Is Hitting Our Staple Crops

The Conversation - Andrew Borrell

Farmers face falling crop yields and growing food demand. Shutterstock

While increases in population and wealth will lift global demand for food by up to 70% by 2050, agriculture is already feeling the effects of climate change. This is expected to continue in coming decades.
Scientists and farmers will need to act on multiple fronts to counter falling crop yields and feed more people. As with previous agricultural revolutions, we need a new set of plant characteristics to meet the challenge.
When it comes to the staple crops – wheat, rice, maize, soybean, barley and sorghum – research has found changes in rainfall and temperature explain about 30% of the yearly variation in agricultural yields. All six crops responded negatively to increasing temperatures – most likely associated with increases in crop development rates and water stress. In particular, wheat, maize and barley show a negative response to increased temperatures. But, overall, rainfall trends had only minor effects on crop yields in these studies.
Since 1950, average global temperatures have risen by roughly 0.13°C per decade. An even faster rate of roughly 0.2°C of warming per decade is expected over the next few decades.
As temperatures rise, rainfall patterns change. Increased heat also leads to greater evaporation and surface drying, which further intensifies and prolongs droughts.
A warmer atmosphere can also hold more water – about 7% more water vapour for every 1°C increase in temperature. This ultimately results in storms with more intense rainfall. A review of rainfall patterns shows changes in the amount of rainfall everywhere.

Maize yields are predicted to decline with climate change. Shutterstock

Falling yields
Crop yields around Australia have been hard hit by recent weather. Last year, for instance, the outlook for mungbeans was excellent. But the hot, dry weather has hurt growers. The extreme conditions have reduced average yields from an expected 1-1.5 tonnes per hectare to just 0.1-0.5 tonnes per hectare.
Sorghum and cotton crops fared little better, due to depleted soil water, lack of in-crop rainfall, and extreme heat. Fruit and vegetables, from strawberries to lettuce, were also hit hard.
But the story is larger than this. Globally, production of maize and wheat between 1980 and 2008 was 3.8% and 5.5% below what we would have expected without temperature increases. One model, which combines historical crop production and weather data, projects significant reductions in production of several key African crops. For maize, the predicted decline is as much as 22% by 2050.
Feeding more people in these changing conditions is the challenge before us. It will require crops that are highly adapted to dry and hot environments. The so-called "Green Revolution" of the 1960s and 1970s created plants with short stature and enhanced responsiveness to nitrogen fertilizer.
Now, a new set of plant characteristics is needed to further increase crop yield, by making plants resilient to the challenges of a water-scarce planet.

Dr Niaba Teme, a sorghum breeder, examines the panicle of a drought-adapted genotype in Mali, Africa. Author provided

Developing resilient crops for a highly variable climate
Resilient crops will require significant research and action on multiple fronts – to create adaptation to drought and waterlogging, and tolerance to cold, heat and salinity. Whatever we do, we also need to factor in that agriculture contributes significantly to greenhouse gas emissions (GHGs).
Scientists are meeting this challenge by creating a framework for adapting to climate change. We are identifying favourable combinations of crop varieties (genotypes) and management practices (agronomy) to work together in a complex system.
We can mitigate the effects of some climate variations with good management practices. For example, to tackle drought, we can alter planting dates, fertilizer, irrigation, row spacing, population and cropping systems.
Genotypic solutions can bolster this approach. The challenge is to identify favourable combinations of genotypes (G) and management (M) practices in a variable environment (E). Understanding the interaction between genotypes, management and the environment (GxMxE) is critical to improving grain yield under hot and dry conditions.
Genetic and management solutions can be used to develop climate-resilient crops for highly variable environments in Australia and globally. Sorghum is a great example. It is the dietary staple for over 500 million people in more than 30 countries, making it the world's fifth-most-important crop for human consumption after rice, wheat, maize and potatoes.

Sorghum with (left) and without (right) stay-green under terminal drought in India. Author provided

 'Stay-green' in sorghum is an example of a genetic solution to drought that has been deployed in Australia, India and sub-Saharan Africa. Crops with stay-green maintain greener stems and leaves during drought, resulting in increased stem strength, grain size and yield. This genetic solution can be combined with a management solution (e.g. reduced plant population) to optimise production and food security in highly variable and water-limited environments.
Other projects in India have found that alternate wetting and drying (AWD) irrigation in rice, compared with normal flooded production, can reduce water use by about 32%. And, by maintaining an aerobic environment in the soil, it reduces methane emissions five-fold.
Climate change, water, agriculture and food security form a critical nexus for the 21st century. We need to create and implement practices that will increase yields, while overcoming changing conditions and limiting the emissions from the agricultural sector. There is no room for complacency here.

Links

• El Niño is over, but has left its mark across the world
• Charcoal rot: a threat to staple food crops in South Africa
• 'CO₂ is food for plants!' What will higher emissions mean for crop productivity?

'Disastrous': Australia's Carbon Emissions Jump As Coal-Fired Power Ramps Up

Fairfax - Peter Hannam

Australia's greenhouse gas pollution jumped in 2015-16 as coal use continued to rise after the scrapping of the carbon price, making it harder to meet its emissions targets.
Overall emissions are up 3.4 per cent compared with 2014-15 and up 7.5 per cent since the Abbott government eliminated the carbon price in June 2014, the Australian Conservation Foundation said, citing new data released under the National Greenhouse & Energy Reporting Scheme.

La Trobe Valley's Loy Yang coal-fired power station is among the big polluters. Photo: Paul Harris

The data suggests that Australia's emissions are set to be higher at the end of the decade than they were in 2000, although credits earned in interim years will enable the country to meet its 2020 goals. The 2030 goal of cutting pollution at least 26 per cent on 2005-levels will be harder to meet the longer annual emissions keep rising.
Hugh Saddler, an honorary associate professor at the Australian National University, said total grid-connected generation – which excludes power plants at mines or other standalone sites – rose 3.3 per cent during 2015-16, and emissions gained 1.7 per cent.
"Although there was a modest improvement in emissions intensity – undoubtedly because of more wind generation driven by the large-scale Renewable Energy Target – it was not enough to offset the relatively larger increase in demand, as consequently total emissions went up," Dr Saddler said.
So-called scope 1 and scope 2 emissions from Australia's electricity sector rose by 2.6 per cent on 2014-15 levels and are up 5 per cent since the carbon tax ended, the conservation foundation said.
"This latest data provides more evidence Turnbull government policies that are supposedly designed to cut Australia's climate pollution are simply not doing the job," Kelly O'Shanassy, ACF's chief executive, said.
"Instead of acknowledging global warming as a national crisis that demands immediate, serious action, the federal government is considering giving Adani a $1 billion loan for a coal-carting railway line [in Queenland] and wants the Clean Energy Finance Corporation to fund new coal-fired power stations," she said.

APRA's blunt climate change warning
The Australian Prudential Regulation Authority's very blunt warning of the obvious physical risks and transition risks of moving to a low-carbon economy. Michael Pascoe comments.

In NSW, emissions from the state's five coal-fired power stations rose 7 per cent in the year, or 3 million tonnes, to 49 million.
"The NSW government last November committed to zero carbon emissions by 2050, but they don't have a plan to get us there," Brad Smith, the NSW Nature Conservation Council's senior energy and climate campaigner, said. "This is a disastrous result caused by the failure of leadership from state and federal governments."
Josh Frydenberg, the federal environment and energy minister, said Australia is on target to beat the 2020 goals by 224 million tonnes, and that more than half of the increased emissions in the past year came from the expansion of LNG production, while agriculture-related emissions fell 3.4 per cent.
"Significant progress has also been made in reaching our 2030 target under the Paris Agreement with an improvement of more than 50 per cent since the last projections," he said. "In fact, Australia's emissions per capita and emissions per unit of GDP are now at their lowest level in 27 years."
However, Mark Butler, Labor's climate spokesman, said the data showed the government's "energy crisis is failing on all three metrics: price, reliability and pollution".
Adam Bandt, the Greens' climate spokesman, said Prime Minister Turnbull was fast becoming a "king of pollution" by "pandering to the climate change-denying Trumps of his party".

Links

• Coral bleaching returns to the Great Barrier Reef
• Green bank receives $1.2 billion coal power plant funding request
• Ross Garnaut’s bright idea
• Australia's emissions rise by 2.2 per cent