How Much Carbon Free Energy is Needed in Coming Years?

Supporting Data

● The Emissions Gap Report 2013.

● United Nations Environment Program (UNEP), November 2013

● Includes projections of world carbon emissions up to 2050 under various scenarios.

Current Emissions● “The most recent estimates of global

greenhouse gas emissions are for 2010 and amount to 50.1 gigatonnes of carbon dioxide equivalent (GtCO2e) per year (range: 45.6–54.6 GtCO2e per year).” UNEP 2013 at page xi

● This estimate can be converted to GtC by the factor 3.67.

● The 50 GtCO2 estimate is equivalent to 13.6 GtC

What is the emission level for 2015?

● UNEP 2013 does not give historical data past 2010. However, assuming business as usual, the projected emissions for 2020 are 59 GtCO2e/yr or 16 GtC/yr.

● Considering the failure of governments to address the problem since 2010, it seems likely that the emission level for 2015 must be about 54.5 GtCO2e/yr or 14.85 GtC/yr.

What should be the target emission for 2020, assuming drastic action?

● “Based on a limited number of new studies, least-cost emission pathways consistent with the 1.5° C target have emission levels in 2020 of 37–44 GtCO2e per year, declining rapidly thereafter.” Id. page xii

● The report assumes 44 GtCO2e/yr in 2020 as a basis for targets set for 2025, 2030 and 2050. This is equivalent to 12 GtC/yr.

What are the emission targets for 2025, 2030, and 2050?

● “In the scenarios assessed in this report, global emission levels in 2025 and 2030 consistent with the 2° C target amount to approximately 40 GtCO2 e (range: 35–45 GtCO2e) and 35 GtCO2e (range: 32–42 GtCO2e), respectively. In these scenarios, global emissions in 2050 amount to 22 GtCO2e (range: 18–25 GtCO2e). These levels are all based on the assumption that the 2020 least-cost level of 44 GtCO2e per year will be achieved.” id at xiii

● 40 GtCO2 is 10.9 GtC/yr, 22 GtCO2 is 6 GtC/yr

According to UNEP 2013, what research supports these

projections?

What interactive climate simulations tools are available to analyze the implications of these projections?

ISAM integrated impacts of climate change simulation. http://climatemodels.uchicago.edu/isam/

KAYA Identity Scenario Prognosticator http://climatemodels.uchicago.edu/kaya/

What can be learned from the ISAM simulator?

● This model was developed at a time when it was assumed that the world could act in a timely manner.

● To be useful, the default values of the simulator must be up dated based on UNEP 2013.

● In order to stabilize emissions by 2100, I have updated the model default values as follows:

Using the KAYA tool to determine feasibility

● The KAYA tool requires an estimate of world population assuming that zero population growth can be reached by 2100.

● According to my source (News, National Geographic): “There's an 80 percent chance, the authors conclude, that the actual number of people in 2100 will be somewhere between 9.6 and 12.3 billion.” http://news.nationalgeographic.com/news/2014/09/140918-population-global-united-nations-2100-boom-africa/

The KAYA tools allows other parameters to be set based on

historical trends. ● Other parameters include GDP per person in

dollars, which is a measure of increasing prosperity and demand for products in the world.

● Also, there is a parameter for energy consumption in Watts per year per GDP dollar.

● And, a parameter for energy efficiency in Tons of Carbon per Watt of energy.

KAYA prediction of carbon free energy needed to reach goals

● The following parameters were set based on the population estimate for 2100 of 12 billion people on the planet.

Conclusions

● The KAYA modeler was too conservative, as can be seen from the fact that the historical fit placed 2015 emissions at 9.5 GtC/yr, while we suspect that the actual number for 2015 is nearly 15 GtC/yr.

● Even with the conservative estimate, the model shows we will need at least 50 TeraWatts of Carbon Free Energy by 2100, beginning with over 10 TeraWatts by year 2020 if we mean to keep CO2 below 500 ppm by 2100.