Just 100 companies have been identified as accountable for more than 70 percent of the world’s greenhouse gas emissions, according to a report published Monday.

The Carbon Majors Report, published in collaboration with the Climate Accountability Institute, found that more than half of industrial emissions worldwide could be sourced to only 25 corporate or state-owned businesses.

The report said the scale of historical emissions is large enough to have contributed significantly to climate change since 1988. The same year the Intergovernmental Panel on Climate Change was established.

Typically, large-scale greenhouse gas emissions data has been collected by country level. However, the Carbon Majors Report focused on fossil fuel producers in order to emphasize the role firms and their investors could play when attempting to tackle climate change in the future.

The highest emitting companies over the last three decades included companies such as ExxonMobil, Shell, and BP.

All three major oil and gas companies have faced heavy criticism for their respective environmental records in the past and have since embarked upon green investments. ExxonMobil announced in May last year it would start exploring carbon capture and storage, while BP and Shell have increased investment in renewables in recent years.