The Role of Biomass in a 100 % Renewable Energy World

Abstract

Recently the Intergovernmental Panel on Climate Change (IPCC) published three parts of the 5th Assessment Report of the IPCC on “Climate Change.” I summarize the three important messages of these reports as follows:

Human influence: The human influence on our climate now appears effectively proven. The report says: “It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.”

Fossil fuels as the main cause of climate change: Burning fossil fuels is the dominating cause for the increase of CO₂ in the atmosphere. The report explains: “There is an uptake of energy in the climate system due to the positive radiative forcing. The largest contribution to total radiative forcing is caused by the increase in the atmospheric concentration of CO₂ since 1750” and further: “Annual CO₂ emissions from fossil fuel combustion and cement production were 9.5GtC in 2011, 54 % above the 1990 level. Annual net CO₂ emissions from anthropogenic land use change were 0.9 GtC on average during 2002 to 2011.” Hence the CO₂ emissions caused by burning fossil fuels are 10 times higher than those of land use change and they are the main cause of climate change!

The chance for mitigation: Yet the IPCC publication contains also an optimistic message. Mankind has still the choice to mitigate climate change in this century. In the report a mitigation scenario is presented with a rather modest climate change. In this IPCC-scenario cumulative CO₂ emissions of 270 GtC are assumed in the period of 2012–2100 as compared to 1685 GtC emissions in the high emission scenario. The report concludes: “Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.” But it does not explain in detail what this means for the energy system. The aim of this article is to answer this question.

This paper explains how fast the energy system has to be changed towards 100 % renewables in order to comply with the mitigation scenario of the IPCC and which role biomass has to play in such a strategy.