Purchase Offsets

*If you need a receipt for your purchase or would like to see our other portfolio options, then don’t purchase via our website. Instead, send an email to info@ostromclimate.com and we’ll get back to you as quickly as we can.

Choose your project portfolio

Now that you’ve decided to counter your individual emissions with an investment in the future of cleaner air, you can choose which project portfolio your offsets will support – close to home or abroad.

Climate Action Portfolio - $26 CDN/TONNE (before tax)

90% of our offsetting customers choose from our Climate Action Portfolio. It’s a collection of high quality offset projects developed to best in class standards from Canada and around the world.

Read about our Climate Action Portfolio projects.

Gold Standard Portfolio - $29 CDN/TONNE (before tax)

The Gold Standard is an internationally-accepted standard for offsets that has been designed to support sustainable development around the world. Investing in this portfolio will promote high quality emission reduction and sustainable economic development around the world.It is aligned closely with the UN Sustainable Development Goals (SDGs). Projects must be completed in developing nations – and have co-benefits (benefits beyond the emissions reductions) that support the 17 SDGs.

Read about our Gold Standard projects.


While the difference in emissions output should not differ significantly from one calculator to another, there are a few reasons as to why this may happen. Some calculators may use different criteria to calculate emissions. Variations in individual behavioural estimates, conversion factors, and accounting for radiative forcing and uplift factors can also affect the carbon emissions output.

Another reason may be that some calculators could be out-of-date, since emissions factors are updated every year.

We recommend that you only use calculators that:

  • provide sources for emissions factors
  • use radiative forcing and account for an uplift factor

We work to ensure that the emissions factors in our calculator are up-to-date, such that we can provide you with the most accurate and detailed representation of your carbon footprint. The emissions factors that we have used for the calculator are:

The IPCC’S “Aviation and the Global Atmosphere” report recommends that both a radiative forcing factor and an uplift factor be included in flight emissions calculations. Condensation trails (contrails) may also impact these calculations.

What is radiative forcing?

Radiative forcing (RF) is the annual mean radiative imbalance in the Earth’s climate system which is caused by human activities. RF predicts changes to the global mean surface temperature, a positive RF contributes to global warming. However, this does not happen uniformly and you can have instances where some regions are warmer or cooler than others. In aviation, RF accounts for the additional climate impacts associated with burning fuel so high in the atmosphere.

What is an uplift factor?

The uplift factor adds 8% to emissions, due to aircraft stacking (circling), and the fact that some routes are not direct (e.g. due to weather conditions, or flying around international airspace).

How do contrails impact emissions?

During flight, airplanes’ engines produce condensation trails (contrails) from the exhaust, putting out an almost invisible thermal blanket of cloud across the sky. While they only last in the atmosphere for a short time, they have a daily impact on atmospheric temperatures that is greater than that from the accumulated CO2 emissions from all aircraft since the Wright Brothers took to the skies more than a century ago.

No, they are not. Carbon offsets are not a charitable donation; they are a purchase to mitigate greenhouse gas emissions. They help with the transition to a low carbon economy by creating a financial incentive for companies/people to create emissions reductions that would not happen otherwise
No, they do not. Carbon offsets are considered a financial instrument/purchase and are therefore taxed normally, so there is no tax deductible on them.