Startups that sell carbon credits are the next big thing to hit Canada’s stock markets. …Nearly a dozen startups are expected to list their shares on Canadian exchanges to finance carbon-credit purchases or invest in climate ventures that generate credits. These carbon credits are in high demand. They are supposed to reduce the amount of carbon in the atmosphere by funding things such as new technologies or forest preservation. …Some recently launched Canadian ventures are creating carbon credits by distributing cook stoves that reduce carbon emissions or by growing new forests, which store greenhouse gases. Others are acquiring carbon credits earned by preventing threatened deforestation. One new business is joining with a company that injects captured carbon emissions into fresh concrete. …The market for credits is now valued at several hundred million dollars, but people involved see it growing into the tens of billions of dollars. [to access the full story a WSJ subscription is required]