Taxes are potentially among the most effective ways of cutting pollution and greenhouse gas emissions, but they are currently – with very few exceptions – underused; and even where used, they are frequently designed in a sub-optimal way.

Cost-benefit analyses and other quantitative appraisals are used in many countries to support decision-making in public policy, including investment projects in sectors such as transport and energy. This paper discusses the range of approaches which can be employed to value changes in carbon emissions in policy appraisalsand presents some case studies and a survey of current practice in OECD countries.

It has become the accepted wisdom that meeting the global climate challenge will require zero net greenhouse gas (GHG) emissions by the end of this century. Read the full op-ed by Gabriela Ramos, OECD Special Advisor to the OECD Secretary-General.

More than 150 countries have submitted their post-2020 Intended Nationally Determined Contributions (INDCs) to the United Nations Framework Convention on Climate Change (UNFCCC). Such contributions are vital to the #COP21 climate change conference in Paris this December.

"Back to the Future" festivities marking 21 October 2015 as the date Marty and Doc travel to the future in the famous film with Michael J. Fox. If only we had a similar time machine allowing us to travel to 2045 to see what the climate has in store to better decide what policies to adopt today. Alas, no time machine has been invented yet but, in the absence of such a cool device, we can rely on climate and economic models...

To increase transparency and improve understanding of different countries’ situations, the OECD has developed an interactive map that brings to life key climate change mitigation statistics and policy settings. The webinar on Monday 16 November 2015, 15h00-16h30 (Paris time) consisted of a summary of the main messages of the report "Climate Change Mitigation: Policies and Progress" and a demonstration of the interactive tool.

Participants to the Arrangement on Officially Supported Export Credits have agreed new rules on official support for coal-fired power plants, including restrictions on official export credits for the least efficient coal-fired power plants, the OECD announced today.

Tackling climate change will require action in three key areas. First, we must strengthen carbon pricing and remove fossil fuel subsidies. Second, we must remove barriers to green investment. And third, we must align policies across the economy to leave fossil fuels behind and improve transparency on climate finance.

The UN Conference on Climate Change (COP21) in Paris 30 November-11 December is a once-in-a-generation opportunity to reach a new international agreement to combat climate change and accelerate our transition to a low-carbon economy. The “carbon entanglement” of our economies is keeping us on a collision course with nature.

OECD urges efforts to better price carbon as new analysis finds that 90% of CO2-emissions are priced below EUR 30 per tonne, a low-end estimate of climate damage, and 60% are not priced at all. Effective Carbon Rates in the OECD and Selected Partner Economies calculates effective carbon rates (ECR) on CO2-emissions from energy use for 41 countries which together use 80% of global emissions.

This is a watershed day for the world and especially heartening for the OECD as one of the first international bodies to call for zero net emissions in the second half of the century, for a price on carbon and for greater efforts to channel finance into the low carbon economy.

The IEA is pleased to announce the second event in its new distinguished speaker series, Big IdEAs, which brings global leaders and decision makers to the IEA to share their views on a range of global issues. On Friday 29 January starting at 11h30, Professor Sir David King, the UK Foreign Secretary’s Special Representative for Climate Change, will speak on "Towards decarbonising the global economy".

Urgent research is needed to assess the possible risks to human health and ecosystems from the ever-increasing amounts of engineered nanomaterials going into household waste and ending up in the environment, according to a new OECD report.

Cloudy head on climate change? Join the webinar on Wednesday 30 March 2016 from 1-2 pm (Paris time) with Professor Per Espen Stoknes on What we think about... when we try not to think about... global warming!

Clearly a revolution in the global economy is needed for a heavy reduction of GHG emissions. You may have heard of Carbon Capture and Storage or CCS. This technology prevents CO2 from fossil fuel combustion from accumulating in the atmosphere.

The initials ‘CCS’ usually stand for Carbon Capture and Storage. However, I was with the team in Paris during COP21 promoting the Cap Global Carbon proposal; the mechanism embodied in Cap Global Carbon is Cap & Share, and it occurred to us that the name ‘Carbon Cap & Share’ has the same initials, CCS. Are these two types of CCS complementary or antagonistic? Are they friends or enemies?

A stern warning for climate change, and our health - Shipping brings us 90% of world trade and has increased in size by 400% in the last 45 years. Cargo ships, tankers and dry-bulk tankers are an essential element of a globalised world economy, but they are thirsty titans and they won’t settle for diet drinks. There are up to 100,000 working vessels on the ocean and some travel an incredible 2/3 of the distance to the moon in one year.

The Paris Agreement is a landmark in collective efforts on climate change and is the result of many years’ hard work. It must now be implemented.

Water is linked to many economic activities, and there are complex channels through which water affects economic growth. The purpose of this report is to provide background information useful for a quantitative global assessment of the impact of water scarcity on growth using a multi-region, recursive-dynamic, Computable General Equilibrium (CGE) model.

Current carbon prices are falling short of the levels needed to reduce greenhouse gas emissions driving climate change, but even moderate price increases could have a significant impact, according to new OECD research.

The world must ramp up its efforts to use natural resources more sustainably and conserve biological diversity and the ecosystems on which we depend for human life, the OECD today told participants at the COP13 Convention on Biological Diversity in Cancun, Mexico.

This study was one of the first attempts to evaluate and quantify the benefits of transboundary co-operation between Georgia and Azerbaijan. A specific framework for inventorying these benefits, taking into account all the different dimensions of transboundary water management, was built and applied to the major transboundary water bodies.

New evidence on the effect of energy prices on outward FDI can provide some reassurance in light of concerns about Pollution Havens.

Climate change is a clear and undeniable challenge that requires a global response. The Paris Agreement represents the careful crafting of a collective effort of over 190 countries to meet this challenge.

This paper presents updated results for the cost of ambient air pollution in 41 countries: the 6 major emerging economies known as the BRIICS – Brazil, Russia, India, Indonesia, China and South Africa – and the 35 OECD member countries.

Fossil fuels continue to dominate the energy mix, with both OECD economies and the BRIICS still relying on fossil fuels for more than 80% of their energy supply.

“National governments must take the lead and do so with a recognition that they are part of a global effort.” Speaking last week at the Munk School of Global Affairs in Toronto, OECD Secretary-General Angel Gurría urged countries not to retreat behind their national borders in dealing with climate change. Read the full blog.

This paper details a methodology for calculating the extent of terrestrial and marine protected areas recorded in the World Database on Protected Areas by country, type and IUCN management categories. The method allows the data on protected areas to be summarised in a harmonised and more detailed way than is currently available, without requiring any additional reporting by countries.

The world’s oceans are being damaged by a constant and unprecedented accumulation of waste known as marine debris. The waste, mostly from effluent human activities, is brought to the oceans through currents and often carried far from where it originated.

With marine biodiversity deteriorating at an alarming rate, there will soon be little left of the “octopus’s garden” that The Beatles once sang about. According to "Marine Protected Areas: Economics, Management and Effective Policy Mixes", pollution, overfishing and rising temperatures have damaged or destroyed 60% of the earth’s marine ecosystems.

Ending poverty and combating climate change: two years after the adoption of the UN Sustainable Development Goals and the Paris Climate Agreement, these inter-related challenges remain as daunting as ever, not least in developing countries.

One focus of tomorrow’s One Planet Summit, organised by President Macron, is “to determine how those working in public and private finance can innovate to support and accelerate our common efforts to fight climate change.”

OECD Secretary-General Angel Gurría announced today at the One Planet Summit in Paris the launch of the “Paris Collaborative on Green Budgeting”, a strategic initiative to assess and drive the alignment of national budgetary processes with the Paris Agreement and other environmental goals.

On the occasion of the One Planet Summit, read our latest OECD Observer articles focusing on the challenges and opportunities for climate action, particularly in the area of green finance and investment.

Action to prevent the risk of major flooding in Paris and the Ile de France region has improved in recent years – particularly after the Seine burst its banks in May and June 2016 – but urban and territorial planning needs to be better adapted, governance strengthened and long-term funding clarified, according to the OECD.

This paper summarises efforts in two West African countries – Mauritania and Guinea-Bissau – to mobilise international finance to sustain the marine biodiversity upon which fisheries depend, and to establish conservation trust funds. The countries study draws on the 2017 OECD report The Political Economy of Biodiversity Policy Reform.

Mr. Angel Gurría, Secretary-General of the OECD, will be in Brasilia on 21st March 2018 to attend the World Water Forum.

The OECD has been awarded the Hassan II World Water Prize by the government of Morocco and the World Water Council in recognition of its work under Secretary-General Angel Gurría to elevate water security as a crucial global issue and the policy guidance it has provided countries around the world on the issue.

This report examines what would be needed to achieve zero CO2 emissions from international maritime transport by 2035. It assesses measures that can reduce shipping emissions effectively and describes possible decarbonisation pathways that use different combinations of these measures; and reviews under which conditions these measures could be implemented and presents concrete policy recommendations.

This paper reviews the existing literature on modelling the macroeconomic consequences of the transition to a circular economy. It provides insights into the current state of the art on modelling policies to improve resource efficiency and the transition to a circular economy by examining 24 modelling-based assessments of a circular economy transition.

The Paris Collaborative on Green Budgeting was launched by the OECD Secretary-General Angel Gurría at the One Planet Summit in Paris on 12 December 2017. It aims to design new, innovative tools to assess and drive improvements in the alignment of national expenditure and revenue processes with climate and other environmental goals.

Hungary has made progress in greening its economy and cutting emissions, but it needs to speed up efforts to replace fossil fuels with renewable energy sources, improve energy efficiency in buildings and promote sustainable transport, according to a new OECD Review.

Mr. Angel Gurría, Secretary-General of the OECD, will be in Prague on 16 July 2018 on an official visit. He will present the 2018 OECD Economic Survey and the Environmental Performance Review of the Czech Republic.

The Czech economy is thriving, with robust employment, expanding exports and falling government debt. Efforts should now focus on boosting workforce skills and innovation to improve labour supply and productivity, further reduce poverty and inequality, and green the economy, according to two new OECD reports.

Governments need to raise carbon prices much faster if they are to meet their commitments on cutting emissions and slowing the pace of climate change under the Paris Agreement, according to a new OECD report.

Public support for metal extraction and processing has received little attention relative to that for the agriculture, energy, or fisheries sectors. This report addresses this knowledge gap by mapping out the most common forms of support provided for primary metals (produced from mineral ores) and secondary metals (produced from scrap).

The transition towards a resource efficient and circular economy has linkages with international trade through the emergence of global value chains as well as trade in second-hand goods, end-of-life products, secondary materials and waste. This paper highlights the interaction of international trade and the circular economy in order to map out potential issues to address and to guide further research areas to explore on this topic.

OECD Deputy Secretary General, Mr. Masamichi Kono, and Shardul Agrawala, Head, Environment and Economy Integration Division, OECD Environment Directorate, presents the key findings of the forthcoming OECD report "Global Material Resources Outlook to 2060: Economic Drivers and Environmental Consequences".

This summer, we witnessed record-breaking heat and extreme weather events across the globe. To address the urgent climate challenge, and meet our broader development goals, trillions of dollars need to be invested in low-emissions and resilient infrastructure.

17-22 November 2018, Sharm El-Sheikh, Egypt. The OECD actively participated in this Conference through an official OECD side event and by taking part in a number of workshops, seminars and other events throughout the conference. Read more on the OECD side-event, participation at the High-Level Segment and the OECD work on biodiversity.