Paris 2024 wants its emissions to be 50% lower than the 2012 and 2016 Games.

"With Birmingham, we are bound by a shared vision," said Georgina Grenon, sustainability director for Paris 2024.

"That vision is of aiming to deliver a spectacular celebration, showcasing the best of our cities and harnessing the power of sports to unite and create long-lasting benefits for society, but also taking care of the impact that these events are going to leave behind.

"Paris, the Olympics and Paralympic Games, are the world's biggest event and we are facing humanity's biggest challenges. So we have set for ourselves the ambition of setting a new model for these Games so that we are aligned with this modern world and what society is asking.

"In concrete objectives, we are reducing our emissions by 50% compared to the average of London 2012 and Rio 2016. We will also offset all of the unavoidable emissions. We want to be the first Games to be fully aligned with the Paris Agreement. In terms of climate ambitions, that is very important."

The Paris Agreement united almost all the world's nations - for the first time - in a single aim to cut the greenhouse gas emissions that are causing global warming.

Agreements were made to "pursue efforts" to limit global temperature rises to 1.5C, and to keep them "well below" 2.0 above pre-industrial times.

Historically, major sporting events have had significant environmental impacts. Construction of venues, as well as travel, energy and food are the biggest contributors to any sport's carbon footprint.

The Tokyo Olympics' post-Games sustainability report

calculated that the event had a total carbon footprint of between 1.96 million and 2.42 million tonnes of carbon dioxide, though it claimed the 2020 event (held in 2021) went "beyond carbon neutrality" through a range of reduction and mitigation measures.

The report added that emissions were lower than they might otherwise have been by 800,000 tonnes of carbon dioxide because Covid-19 restrictions meant there were few fans in attendance.

The football World Cup in Qatar this year has plans to limit its impact but it is estimated by organisers Fifa to produce around 3.6 million tonnes of carbon dioxide, which would be more than some countries' annual emissions.

Birmingham 2022 aims to leave a "carbon-neutral legacy", with one key strand of its approach being to reuse or renovate existing sites, rather than building new ones from scratch.

Paris has adopted a similar stance.

"In order to reduce our emissions by 50%, we have to make very strong decisions very early on, such as using 95% of existing or temporary infrastructure," said Grenon. "So we are building very, very little. And wherever we are building, we are building low carbon and it has to have a use afterwards."

Paris organisers have taken advice from their colleagues in the UK about how they have approached all elements of planning for an environmentally sustainable Games.

"We really found that it was important to share best practices among large sports events organisers," added Grenon, who said discussions had taken place with Birmingham organisers on a range of sustainability issues, including approaches to catering and waste management.

"This allowed us to learn from Birmingham and take their experience into account when assessing our own options for the larger Olympic and Paralympic Summer Games operation."