How bad is climate change?

• Physical indicators alert to climate impacts, but cannot assess the significance of climate change for human needs and well-being.
• Standards and targets help evaluate the impacts, but are judgmental.
• Monetary measures and models suffer from controversial valuations and uncertainties about future impacts of climate change.
• We do not know the damage of climate change, neither now nor in the future.
• Greened national accounts can measure the maintenance costs of past pressures on climate for an initial setting of policy instruments.

Natural scientists and environmental organizations predict catastrophe if global warming continues at the current pace. Their indicators warn us about different hazards of climate change but fail to show their overall impact on human needs and well being. Environmental economists model future costs and benefits of economic activities to compare them with the expected damage and mitigation costs of climate change. The wide range of their estimates reflects different model assumptions and controversial pricing of non-market effects. We do not know, therefore, the significance of climate change, especially in comparison to other environmental and socioeconomic costs and benefits. Integrated environmental-economic accounts can reduce the ambiguity of modelling by measuring the economic costs of climate change during a past accounting period. Climate policy rather than politics could be the result.