pollution tax environmental economics 9 climate change 7 carbon emission 5 Carbon pricing 3 Carbon tax 3 Environmental policy 3 Environmental protection 3 International trade 3 emission control 3 environmental policy 3 Carbon 2 Carbon taxes 2 China 2 Climate change 2 Climate policy 2 Taxation 2 air transportation 2 carbon dioxide 2 conceptual framework 2 cost-benefit analysis 2 emissions trading 2 international trade 2 trade-environment relations 2 Air passenger duty 1 Air travel 1 Blue carbon ecosystems 1 Border tax adjustments 1 Briquetting 1 CO2 emissions 1