Many companies are moving toward renewable energy, but business relationships can add a stronger incentive.

For example,Intel rates its suppliers' greenhouse gas emissionsas one factor in doing business with them.

Such business relationships are an important part of reducing so-called Scope 3 emissions.

Scope 1 emissions are released directly by a company, for example with trucks it uses to ship products.

Scope 2 emissions are generated by a company’s electrical power generation.

Scope 3 emissions are those generated by a company’s suppliers and customers.

Apple estimates that customer user of Apple products accounts for 22% of the company’s total carbon footprint.

Reducing emissions is critical to limiting the rise of the global average temperature.

Climate change is bringing more severe storms and droughts, hurting biodiversity and elevating sea levels.

Some companies are going farther than carbon neutrality.

Microsoft is working toreverse carbon emissions from its entire corporate history, andGoogle has already reached that stage.

Apple aims to be carbon neutralfor Scope 1, 2 and 3 by 2030.

For that deadline, Apple also plans to cut emissions of other greenhouse gases like methane and nitrous oxide.

Big tech companies increasingly have used power purchase agreements with energy companies to push them toward renewable power.

In some cases, though, Apple has gone further with direct investments in renewable power projects.