What are Offsets?


The consumer section of the CORE website provides a non-technical overview and introduction to carbon offsets, their pros their cons, how they work and how to choose the right ones.

To get started also read the sections:
What Makes Good Offsets?

Are Offset a Scam?
Introduction to Offset Markets

You'll also find a list of Studies that Rate Offset Providers and a Extensive List of Offset Providers.

We welcome your suggestions and comments. Please write to offsetreview@sei-us.org


In order to prevent serious climate disruption and to keep global temperature increase below 2 degrees Centigrade, current climate science suggests that atmospheric greenhouse gas (GHG) concentrations need to peak below 450 parts per million (ppm). This requires global emissions to peak in the next decade and decline to roughly 80% below 1990 levels by the year 2050 (find a good summary here). Such dramatic emissions reductions require a sharp move away from fossil fuel, significant improvements in energy efficiency and substantial reorganization of our current economic system.

Public awareness of the threat of climate change has risen considerably in the last couple of years and an increasing number of businesses, organizations and individuals are looking to minimize their impact on the climate. To effectively address the threat of climate change, we need comprehensive and stringent policies to reduce greenhouse gas (GHG) emissions at national and international levels. At the same time, voluntary individual and corporate climate action can be essential for creating the public awareness and constituency needed for policy change.

Individuals and organizations can most effectively lower their own carbon footprints by improving energy efficiency (e.g. in their homes, offices, or factories), relying on lower-emission products (e.g. buying locally grown food), and changing consumption patterns (e.g. home size, travel choices).

Beyond this, carbon offsets are gaining prominence as a tool to compensate for emissions. By paying someone else to absorb or avoid the release of a ton of CO2 elsewhere, the purchaser of a carbon offset can aim to compensate for or, in principle, “offset” their own emissions. This is possible because climate change is a non-localized problem; greenhouse gases spread evenly throughout the atmosphere, so reducing them anywhere contributes to overall climate protection.

Carbon markets are already a substantial economic force and will likely grow considerably over the coming years. Yet carbon offset have not been without critics... read more...