Most but not all economists view carbon pricing as most effective to combat carbon emissions, whereas other policies are widely applied and highly debated. We quantify the effectiveness of climate policies in the form of pricing carbon and subsidizing renewable energies for Germany's and Britain's power sectors. While Germany relies on heavy subsidies for renewables but on a weak price for carbon certificates (EUA) from the EU Emission Trading System (ETS), its emissions hardly declined. To underpin the low EUA price, Britain introduced a unilateral tax on power sector emissions, the Carbon Price Support (CPS). Within only five years, carbon emissions declined by 55%. Our results demonstrate that in the power sector, even a modest carbon price (∼€30/tCO₂) can induce significant abatement at low costs within a short period as long as “cleaner” gas plants exist to replace “dirty” coal plants. We also find that carbon pricing is superior to subsidizing wind or solar power in these two countries.

大多数（但不是全部）经济学家认为碳定价是对抗碳排放最有效的方法，而其他政策则得到广泛应用和高度争议。我们以定价碳和补贴德国和英国电力部门的形式量化气候政策的有效性。尽管德国依靠可再生能源的大量补贴，但欧盟排放交易体系（ETS）的碳证书（EUA）价格低廉，其排放量几乎没有下降。为了支撑低EUA价格，英国对电力部门的排放量征收了单边税，即碳价支持（CPS）。在短短五年内，碳排放量下降了55％。我们的结果表明，在电力部门，即使是适度的碳价（约30欧元/吨CO ₂），只要有“更清洁”的煤气厂来代替“肮脏”的燃煤厂，就可以在短时间内以低成本诱导大量减排。我们还发现，在这两个国家中，碳定价优于补贴风能或太阳能。