A warming planet is not the only impact of higher carbon dioxide levels in the atmosphere; it is a greener planet as well. This has been one of the striking, and controversial, scientific confirmations of the year. Source: The Australian
The greening of the planet because of an increase in leaves on plants and trees is equivalent to twice the size of the continental US, a long-range study found.
It strengthens the case for changing our land use to combat human greenhouse gas emissions, and means using bioenergy — renewable energy from living organisms — may solve our energy security of supply problems.
It also may help to create a billion dollar economy based on plants that can help our energy troubles.
The findings, published in Nature Climate Change, give weight to arguments that climate change can have positive as well as negative impacts. Some are quick to assert that the negatives of higher CO2 and climate change — rising temperatures, sea level changes and greater chance of forest fires — outweigh the positives.
Nonetheless, NASA’s report this year on the research findings of a group of 32 authors from 24 institutions in eight countries is unambiguous. Between 25% and 50% of Earth’s vegetated lands show significant greening across the past 27 years largely because of rising levels of atmospheric carbon dioxide.
Increased leaf cover has been the result of higher rates of photosynthesis, the process through which plants chemically combine carbon dioxide from the air with water and nutrients tapped from the ground to produce sugars, the main source of food, fibre and fuel for life on Earth.
Study co-author Ranga Myneni, a professor in the department of earth and environment at Boston University, says results show that carbon dioxide fertilisation is responsible for 70% of the greening effect — higher than anticipated.
Nitrogen land cover change and climate change due to temperature, precipitation and sunlight changes make up the rest.
Lead author Zaichun Zhu, from Peking University, says the extent of greening across the past 27 years “has the ability to fundamentally change the cycling of water and carbon in the climate system”.
Co-author Shilong Piao, of the college of urban and environmental sciences at Peking University, says the study does not address the connection between greening and carbon storage in plants. However, other studies report a greater take-up of carbon stocks on land since the 1980s, he says.
The emerging research on “global greening” is not given the attention it deserves, says science writer Matt Ridley.
“The climate change lobby is keen to ensure that if you hear about it at all, you hear that it is a minor thing, dwarfed by the dangers of global warming,” he says. “It could be the other way around; greening is a bigger effect than warming.”
But the report findings are not a “get out of jail free card” regarding man-made emissions of greenhouse gases says Richard Betts, chair in climate impacts at the University of Exeter.
“There are a wide range of consequences of these emissions,” Betts says. “Some could be seen as positive, such as enhanced crop growth due to higher CO2, but most are generally viewed as detrimental such as warmer, drier climate leading to increased risk of forest fires.”
The Zhu paper arguably represents a “consensus” statement of the primary global community of scientists working on the topic, says US climate scientist Judith Curry. And it “highlights the very substantial uncertainties in our quantitative understanding of the global carbon budget”.
The paper “alters the dynamics of calculating the social cost of carbon, in the direction of a lower cost”, Curry says.
The Zhu report is one of two recent signposts that highlight the greening of the planet and indicate the future for secure energy and the emergence of a new multi-billion-dollar economy based on plants.
Another is the emerging, humiliating, confirmation from South Australia’s living experiment that replacing fossil fuels with intermittent renewable energy will be more difficult than previously imagined.
In the great circle of life, both things can be connected. One conclusion is that bioenergy and other land-use measures such as reduced land clearing can play a greater role in meeting Australia’s carbon emissions targets. For this, greater plant productivity can be only a good thing.
Bioenergy involves using carbon-rich waste from agriculture and industry to produce heat and electricity. The energy produced can be cheap, abundant and reliable. As with other renewable energies, power and heat from bioenergy is generated closer to where the energy and heat is used.
Expanded further to include bio-engineering to produce chemicals, fuels, synthetic rubber, cosmetics, detergents and textiles, “biofutures” is considered to be a multi-billion-dollar industry of the future.
Bioenergy and biofutures are experiencing rapid growth in Australia. Queensland, in particular, has a long experience with using sugar cane waste for power and heat production.
The state government also has identified biofutures as a significant economic opportunity for the tropics. But, as with carbon capture and storage, bioenergy has been something of an ugly duckling of the renewable energy suite.
First, bioenergy competes for funding with more favoured renewable energy technologies such as wind and solar. And there have been false starts, including the rush to ethanol from corn for transport fuels, robbing arable land from food production.
Critics claim this weakened food security, led to food price inflation and did not result in net carbon dioxide emissions savings.
In Australia, bioenergy faces fierce opposition from environmental groups, which consider it to be a potential threat to native forests if harvest waste is diverted to the furnace as a low-value replacement for woodchip exports.
The forest and bioenergy industries claim burning forest waste for power is uneconomic even with a subsidy. Increasingly, however, bioenergy is finding a place. And some believe there is a message in nature’s response to rising CO2 levels with more plant growth.
The Australian Renewable Energy Agency says bioenergy offers the potential for economic benefits including increasing energy security, reducing greenhouse gas emissions and stimulating regional development. Victorian farmer Alan Lang is a director of the World Bioenergy Association.
He has argued a lonely case for bioenergy in Australia for many years. In Europe, bioenergy is the source of about 63 per cent of renewable energy overall. But according to Bioenergy Australia, less than 1% of domestic electricity is generated by bioenergy.
A bioenergy road map published by the Clean Energy Council suggests that by 2020 the contribution from biomass for electricity generation could be 10,624 gigawatt hours a year, or six times the present generation. By 2050 Australia could be generating more than 73,000GWh a year of bioelectricity, more than double the total requirement of the present renewable energy target.
And for transport fuels, CSIRO has identified potential for second-generation biofuels to become a $45 billon market.
The Queensland government is promoting research and development in biofutures, announcing this week that it is investing $5 million to get bio-industrial products off the laboratory bench and into the market place.
Queensland Innovation Minister Leeanne Enoch says bio-based products are the next generation of products.
“These products are sourced from non-food crops, such as oilseed trees and algae, and agriculture waste such as bagasse to yield products including aviation fuels, diesel and higher value chemicals,” she says.
Development Minister Anthony Lynham says Queensland’s aim is to become the Asia-Pacific’s biofutures hub with a $1bn sustainable export-oriented biotechnology and bioproducts sector. Internationally, a 2010 World Economic Forum report said converting biomass into fuels, energy and chemicals had the potential to generate more than $230bn to the global economy by 2020. But by 2014 the global biorefinery products market had reached almost $438bn.
The World Economic Forum now expects the sector to reach $1.128 trillion by 2022.
Lang says bioenergy is on the agenda nationally with operating plants in South Australia, Queensland, Tasmania, Victoria and NSW.
The cost of bioenergy is already competitive with onshore wind when the combined heat and electricity generation are considered, he says. And there is scope for Victoria by 2030 to produce energy and heat from up to 50 small to medium power plants distributed across the state and fuel led by straw, plantation harvest residues, and combustible non-recyclable municipal solid wastes.
“This would be significant in terms of job creation, reduction in (greenhouse gas) emissions and supply of on-demand renewable electricity, plus industrial heat and steam supply,” Lang says.
The figures do not include biomass from native forestry management sites. Nor they do they allow for the possibility of farmers responding to market signals and producing more biomass from expanded farm forestry and dedicated energy plantings such as short-rotation woody coppice crops.
There are similar opportunities in other states but, relative to the amount of funding earmarked for other sources of renewable energy, the amounts are paltry.
According to South Australian government reports, about $7.1bn has been invested in that state in renewable energy. But South Australia’s bioenergy program is considering spending $150,000 across the next two years to identify opportunities.
Bioenergy Australia says there would be considerable direct and indirect benefits associated with a vibrant biofuels industry in Australia.
The biofuels industry would create a new stream of export revenues. The diversification of markets in agriculture and forestry would stabilise these sectors and serve as a stimulus for Australian manufacturing.
And these benefits would translate Australian and imported innovation into economic growth — all coupled to sustainability and climate change mitigation. But this is a message that still struggles to be heard.
