Models of climate change that the UN Intergovernmental Panel of Experts and decision makers use to
Negative emissions technologies, often called NETs, remove carbon dioxide from the atmosphere.
The three most widely studied approaches are:
- bioenergy with carbon capture and storage, which involves growing crops for fuel and then collecting and storing CO2 from the burned biomass;
- planting more forests;
- direct air capture, an engineering process for separating CO 2 from air and storing it permanently, probably underground.
“The problem is that no one has tried thesetechnology on a demonstration scale, not to mention the massive levels needed to offset current CO2 emissions, ”said Andres Clarence, Professor of Systems Engineering and Environment at UVA Engineering
After the Paris Restriction Agreementglobal warming to 1.5 degrees Celsius, signed by world leaders in 2015, an increasing number of corporations are committed to achieving zero carbon emissions over the next decades. Microsoft has made a commitment to reducing its carbon footprint since its founding in 1975.
For a new study, a team of scientistsused an integrated model - one of those relied upon by the UN - the Global Change Assessment Model. The model was developed at the University of Maryland, which runs the Joint Global Change Research Institute in partnership with the Pacific Northwest National Laboratory. They compared the impact of three negative emissions technologies on global food supply, water use and energy demand. The work examined the role of the presence of direct air capture in future climate scenarios.
Biofuels and reforestation take up hugeland and water resources required for agriculture and natural areas; biofuels also contribute to fertilizer pollution. Direct air capture uses less water than growing biofuels and trees, but it still requires a lot of water and even more energy - mainly from fossil fuels, which negates some of the benefits of carbon dioxide removal. Until recently, direct airflow technologies were also considered too expensive to be included in emission reduction plans.
“Direct air entrainment can soften - but notEliminate — the harshest trade-offs arising from land competition between agricultural land and land needed for new forests and bioenergy, ”Furman and Clarence wrote in the accompanying blog post.
According to the researchers, the costs thatremain over time, grow, making decisive and versatile action to reduce carbon dioxide emissions and remove it from the atmosphere even more urgent.
We need to move away from fossil fuels.even more aggressive than many institutions assume. Negative emission technologies are a pillar of the UN and many countries expect them to one day save us, but they will have side effects that we must be prepared for. It's a huge gamble to sit idly by for the next decade.
Andres Clarence, professor in the Department of Engineering Systems and Environment, UVA Engineering
The new study could help the world avoid some of the mistakes that can arise from ill-conceived initiatives, scientists conclude.
Read also
Humanity will exhaust the permissible resources of the Earth tomorrow. What does it mean?
Astronomers see how a black hole emits flickering gamma rays
There may be more rogue planets than stars in our galaxy