Why does your electricity bill rise when carbon gets more expensive? What is the EU ETS, and how does it affect your business? Are rooftop solar panels worth it? The CO₂ Library answers questions like these in plain language, with verified facts and free tools.
Here you'll find guides to carbon dioxide emissions, the price of carbon, European climate policy and the technologies changing energy, from solar power to carbon capture.
Where to start
- The Paris Agreement: what has changed for CO₂ emissions in ten years, and what comes next.
- EU ETS: who pays and who benefits: emission allowances (EUAs), CBAM and ETS2 in plain English.
- Carbon pricing: who really pays, and how to make the transition fair.
- CO₂ regulations by sector: energy, industry, transport, buildings, farming and finance.
- Urban green infrastructure: how trees and green roofs cool cities and cut CO₂.
- e-fuels: turning CO₂ into fuel: when they genuinely help the climate, and when they don't.
- MOFs and carbon capture: the Nobel Prize-winning materials behind new CO₂ capture.
- Biomass microgrids for islands: clean power from olive pits, prunings and farm waste.
Browse every article in the CO₂ Library.
Free CO₂ tools
Measure, compare, explore. Everything runs in your browser, with no sign-up:
- CO₂ calculator: how much CO₂ you save by switching to solar or wind.
- Emissions map by country: which countries emit the most, year by year.
- Carbon literacy quiz: how much do you know about CO₂ and carbon markets?
Find every tool, including footprint calculators and an EU ETS auction simulator, on our Tools page.
Glossaries
- CO₂ Term Glossary: the language of climate, emissions and carbon markets.
- Logistics Glossary: freight and supply chain terms, plus the "green" terms of transport.
Who the CO₂ Library is for
- Households: to understand what's behind energy costs and which investments, such as energy upgrades, solar panels and heat pumps, make sense.
- Businesses: for carbon footprints, obligations under the EU ETS and CBAM, and sustainability reporting.
- Students and teachers: for reliable, clear explanations and interactive material for the classroom.
- Energy and environment professionals: for a quick update on policy and technology.
How we work
Our articles are based on public, recognised sources such as the European Commission, the European Environment Agency (EEA), Eurostat, the Global Carbon Project and the IPCC. We update articles when rules or data change, and every article shows when it was last updated. Our content is for information only and is not investment or legal advice.
Start with the topic that matters to you, and share the CO₂ Library with anyone who wants to understand the energy transition better.

