“Investments and public finance in a green, low carbon, economy”

The paper evaluates the impacts on investments and public finance of a transition to a green, low carbon, economy induced by carbon taxation. Four global tax scenarios are examined using the integrated assessment model WITCH. Taxes are levied on all greenhouse gases (GHGs) and lead to global GHG concentrations equal to 680, 560, 500 and 460 ppm CO2-eq in 2100. Investments in the power sector increase with respect to the Reference scenario only with the two highest taxes. Investments in energy-related R&D increase in all tax scenarios, but they are a small fraction of GDP. Investments in oil upstream decline in all scenarios. As a result, total investments decline with respect to the Reference scenario. Carbon tax revenues are high in absolute terms and as share of GDP. With high carbon taxes, tax revenues follow a “carbon Laffer” curve. The model assumes that tax revenues are flawlessly recycled lump-sum into the economy. In all scenarios, the power sector becomes a net recipient of subsidies to support the absorption of GHGs. In some regions, with high carbon taxes, subsidies to GHG removal are higher than tax revenues at the end of the century.

► Costs, investments and tax revenues induced by carbon taxes are only loosely related. ► Investments in power generation increase only with stabilization targets below 550 ppm CO2-eq. ► The carbon taxes induce an overall contraction of investments. ► Tax revenues can be as high as 20% of GDP and follow a “carbon” Laffer curve. ► Subsidies for absorption of GHG may be higher than carbon taxes at the end of the century.