COP21 Greenpeace protesters
Greenpeace activists during a protest at the COP21 United Nations climate change conference.Getty

On 30 November the UN Climate Summit began in Paris, bringing together world leaders in an attempt to secure an internationally-binding deal on combating climate change. The deal will aim to keep global warming below 2C and see countries worldwide making binding pledges to cut their carbon emissions.

While world leaders debate the details of the climate deal, a number of businesses have also been doing their part to tackle climate change. In the run up to COP21, many have pledged their commitment to adopting renewable energy or have announced further work in transitioning to carbon-free operations.

IBTimes UK has rounded up some of the most noteworthy companies that are leading the fight against climate change.

1. Microsoft

Microsoft has been powered 100% by renewable energy since 2014 through purchasing renewable energy credits and investing in wind turbines and onsite solar panels at their data centres. Microsoft invested in 520 acres of forest land near Mount Rainier National Park to offset their carbon emissions. In November 2015 the company announced that they would be increasing direct purchase of renewable electricity that they use.

Rob Bernard, Chief Environmental Strategist at Microsoft, told the Climate Group: "We are committed to increasing our purchase of green power and making long-term purchase agreements to power our facilities with local renewable energy. [In 2015] we purchased more than 3.2bn kilowatt hours of renewable energy."

2. Unilever

Making the announcement at COP21, Unilever said that they would be carbon positive by 2030 and would get all their electricity from renewable energy. The company also pledged to stop coal usage within the next five years.

In 2014 Unilever's CEO Paul Polman received a Lifetime Achievement award from the Rainforest Alliance as a result of the company's work with the organisation. Unilever sources 100% of their palm oil sustainably and roughly 50% of the company's tea originates from Rainforest Alliance Certified farms. They are also reported to be working towards sourcing 100% of their raw agricultural materials from sustainable origins.

Keith Weed, CMO of Unilever, said: "Some people ask me, how can you have a business case for low carbon? I say how can you have a business plan for wrecking the planet."

3. Adobe

With the invention of the PDF, Adobe became the first company to mark the beginning of a paperless office by reducing the need to print documents. In December 2015 the company took their commitment to the environment even further when they pledged to operate on 100% renewable energy by 2035. Adobe have also made significant commitments to clean water access by reducing their water consumption by more than 60%.

Michelle Crozier Yates, Director of Corporate Responsibility at Adobe, said: "COP21 is a critical milestone toward a global commitment to stopping climate change. Adobe is proud to be one of the companies leading the way."

4. Google

Until December 2015, Google was already leading the way in clean energy by pledging to "purchase more renewable energy than any other company". But now Google has gone a step further towards achieving their goal of powering all their activities with clean energy. They have been signing "power purchase agreements" that will allow them to buy clean energy in long term contracts. The electricity is then used to power their data centres, which are currently major consumers of power. Google aim to triple their purchase of renewable energy by 2025, meaning that Google searches, emails and everything else linked to the search engine are increasingly being powered by wind and solar energy.

Additionally, Google has announced a fund of $2.5bn (£1.6bn) for 22 renewable energy projects around the world, including in Germany and Kenya. Announcing the programme, a spokesperson for Google said: "These investments have been in some of the largest and most transformative renewable energy projects in the world, with a goal to help drive renewable energy development not only as a customer but as an investor, and bring down costs for everyone."

Speaking at COP21, John Woolard, Vice President Energy at Google, said: "Google is the largest corporate renewable energy buyer in the world but we still need every company in the world to follow us, as the scale needed is staggering. Solar and wind prices have dropped dramatically over the last decade but it's not enough. There is never a single solution."

5. Apple

In November Apple announced that their operations in Singapore would be fully powered by solar energy by the beginning of January 2016. The move makes them the first company in Singapore to be powered 100% by renewable energy, which will be provided mainly through rooftop solar installations.

Lisa Jackson, Apple VP of Environment, Policy and Social Initiatives, told Clean Technica: "Climate change is one of the great challenges of our time, and it's going to take determination and innovation to make the much-needed transition to a green economy. This deal will cover all of our electricity needs in Singapore, including our 2,500-person corporate campus and new retail store."

Ahead of COP21, Apple CEO Tim Cook said that each Apple product is recyclable, energy efficient and free of toxins. The company is also building the country's largest private solar farm to supply their data centres with 100% renewable energy.

6. ING

Dutch multinational banking service ING, announced in December 2015 that they are committed to ensuring 100% renewable energy for all its operations worldwide by 2020. The firm has been climate-neutral since 2007 by offsetting their emissions, while they have also set targets to reduce their CO2, waste and water footprint by 20% by 2020. The initiatives were set up as part of an internal programme to reduce their direct environmental impact.

Roel Louwhoff, Chief Operations Officer of the ING Environmental Program, said: "This move sends a signal both internally and externally that we are serious about doing what we can to combat climate change. We'll continue to look critically at where we can improve and take an aggressive approach to meet our direct footprint goals."

7. Philips

On 9 December Dutch technology company Philips pledged to reduce their carbon footprint to zero by 2020. Between 2007 and 2015, Philips say they reduced their carbon footprint by 40% but wants to continue and achieve carbon neutrality within the next five years. They have said that they plan to do this by reducing energy consumption in its operations, with a specific focus on cutting down on energy use and business travel. They have also pledged to power all their global operations with renewable energy by 2020, having already increased their use of renewables from 8% to 55% in six years.

Speaking at COP21, Harry Verhaar, Head of Public and Government Affairs at Philips Lighting, said: "The relative conservatism of many countries' INDC pledges can be explained in part by the enduring misconception that cutting carbon emissions and improving energy efficiency require sacrifice – either financially or in quality of life. But energy efficiency represents a valuable opportunity with huge economic, social and environmental benefits waiting to be unlocked."