Policies to keep us within planetary boundaries

The Planetary boundaries concept was first developed by Rockström et al. in 2009, where scientists proposed quantitative planetary boundaries within which humanity can continue to develop and thrive. Building on this concept a publication in the journal Nature Communications looks at how policies to stay within one boundary can affect other boundaries. The research team found that a carbon tax policy in combination with cuts in biofuel subsidies could alleviate pressures on all planetary boundaries.

Economist Johan Gars (Beijer Institute) explains the findings further.

The planetary boundaries

The Earth has been in a remarkably steady state over the last 10,000 years, but human activities since the industrial revolution are now starting to threaten its balance. Rockström and colleagues developed a list of nine Earth system processes (ESPs) that are critical to maintaining a stable global environment: biogeochemical flows, ocean acidification, freshwater use, land-use change, biodiversity loss, atmospheric aerosol loading, ozone depletion, and chemical pollution. There are also nine corresponding planetary boundaries beyond which mankind may not proceed without risking potentially catastrophic consequences.

A new model reveals the linkages between boundaries

Since these ESPs are interlinked, the research team led by Beijer Institute researchers in collaboration with colleagues from Uppsala University, Sweden and Georgetown University, USA, developed a stylized but empirically grounded framework for analysing these interlocking processes. With the help of this integrative assessment model they assessed how the main drivers of the planetary boundaries would be affected by stricter climate policies, exemplified here with a global carbon pricing policy.

They found that such a policy not only had a positive effect on carbon emissions, but on most other planetary boundaries as well. However, it would worsen the pressures on land use and water, largely as a consequence of a resulting increase in the incentive to produce biofuel. But by extending the model with a biofuel policy it showed that the combination of carbon pricing and reduction in biofuel subsidies appears able to ease all of the planetary pressures.

The work goes on

A new grant from the Swedish research council Formas, will enable the team to further investigate policy effects on the planetary boundaries as well as on important aspects such as food prices  using this multiboundary perspective. This is important before translating these results to actual policy advice.

Engström G., J. Gars, C. K. Krishnamurthy, D. Spiro, R. Calel, T. Lindahl and B. Narayanan. 2020. Carbon pricing and planetary boundaries. Nature Communications 11(4688).

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