We have 10 years to give up fossil fuels

The next 10 years will be “critical” for the planet to take necessary steps to mitigate climate change, according to researchers from the International Institute for Applied Systems Analysis (IIASA). That’s based on a global carbon model the team used to study outcomes of climate change based on various energy supply scenarios.

It’s the latest in a string of alarming studies released in the past week exploring our rapidly warming planet.

Global map of the February 2017 LOTI (land-ocean temperature index) anomaly shows that North America and Siberia were again much warmer than the 1951–1980 base period, and that Europe was relatively warm. Credit: NASA/GISS.

“Barring unforeseen and transformative technological advancement, anthropogenic emissions need to peak within the next 10 years, to maintain realistic pathways to meeting the COP21 emissions and warming targets,” researchers said in their study.

The model looked at global carbon release and carbon removal through natural and anthropogenic processes, and took into consideration things like agriculture, land use, food production, bioenergy and carbon uptake that occurs in natural ecosystems.

The findings are invigorating if not alarming: based on its projections, the world’s anthropogenic-based energy and land-use systems will need to be producing zero net greenhouse gas emissions “well before” 2040 in order to keep the Earth’s average temperatures from rising above 1.5 degrees Celsius by 2100 — the target that emerged from the Paris agreement reached in 2015.

The study modeled four energy scenarios, from status quo reliance on fossil fuels to more aggressive transitions to renewable energy sources. Fossil fuel consumption will need to shrink to just 25% of the global energy supply (down from the current 95%) if we’re to avoid getting cooked (metaphorically speaking, of course). The rest of our energy supply will have to come from renewables (like solar and wind), which will need to grow about 5% per year to keep our planet under the 1.5 degree threshold.

Nominal demand in the (a) Fossil Fuels, (b) BAU, © RE-Low and (d) RE-High scenarios is shown as time series in each panel. Energy profiles in year 2100 of alternative pathways, used to determine model sensitivity to primary energy demand, are displayed as columns at right. At bottom, time series of fossil fuel market share (as a percentage of total energy consumption) and atmospheric CO2 concentration are displayed at quarter-century intervals. Source of historical data on total primary energy demand: International Energy Agency. Source: Nature Communications

Failure to do so will see us living on a “well-done” planet. Continued reliance on fossil fuels at today’s levels, with renewables growing 2–3% per year, will see global average temperatures reach a searing 3.5 degrees Celsius above pre-industrial levels.

To be clear, that’s the path we’re on today. Renewables grew 2.6% globally between 2013–2014. Things are looking better for 2016, but even with more robust growth in renewables, we’ll still be on track to see a temperature rise of 2.5 degrees Celsius without investments in “substantial negative emissions technologies,” according to researchers.

We have a lot of work to do. And by “we” I really do mean we. All of us. As the study notes, demand side responses to climate change could make or break our energy transition.

“Earlier work on mitigation strategies by IIASA has shown the importance of demand-side measures, including efficiency, conservation, and behavioral change,” said IIASA Energy Program Director Keywan Riahi, who also contributed to the study. “Success in these areas may explain the difference between reaching 1.5 degrees Celsius instead of 2 degrees Celsius.”

The team published their study and findings in Nature Communications. It’s the first published study that’s made use of the FeliX model, a publically-available system dynamics model of social, economic, and environmental earth systems and their interdependencies.

Source: Walsh, B. et al. Pathways for balancing CO2 emissions and sinks. Nat. Commun. 8, 14856 doi: 10.1038/ncomms14856 (2017).