May 22 (Reuters) - The world's biggest oil and gas companies have set varying targets to reduce greenhouse gas emissions from their operations and the combustion of the products they sell.

Scientists say the world needs to cut greenhouse gas emissions by around 43% by 2030 from 2019 levels to stand any chance of meeting the 2015 Paris Agreement goal of keeping warming well below 2 degrees Celsius (3.6 Fahrenheit) above pre-industrial levels.

Direct comparisons of the oil companies' climate plans are difficult as they emphasise different approaches with regards to intensity-based targets and how to include greenhouse gases from the combustion of their fuels - known as Scope 3 emissions.

Intensity-based targets measure the amount of greenhouse gas (GHG) emissions, such as methane and carbon dioxide, per unit of energy or barrel of oil and gas produced.

That means absolute emissions can rise even if the headline intensity metric falls - for example with the addition of renewables or biofuels to the product mix.

Reducing emissions will require a well-functioning market for carbon, the scaling up of carbon capture and storage technology, and the development of competitive uses of hydrogen, many of the companies have said.

The table below shows details by company (in alphabetical order).

Notes:

1) Scope 1 refers to emissions from a company's direct operations, such as a diesel generator on an offshore platform.

2) Scope 2 emissions include planet-warming gases from the power a company uses for its operations, such as gas-powered electricity, and from its fleet of vehicles.

3) Scope 3 includes emissions from the combustion of the products a company sells, such as gasoline or jet fuel. Typically these accounts for over 90% of emissions at an integrated oil and gas firm.

(boed=barrels of oil equivalent per day)

Written and compiled by Shadia Nasralla; editing by Barbara Lewis

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