The global fight against the impacts of climate change is a generational challenge like no other. This is a shared mission, but it is increasingly clear that levels of distrust and scepticism are running high.

The strident campaign by youth activists – such as Greta Thunberg – has challenged the status quo and highlighted the collective responsibility on current leaders to deliver change.

I believe strongly that we must collectively do all we can to demonstrate through our actions that climate promises should not be dismissed as “empty” or characterised by Greta and her contemporaries as little more than “blah blah blah”.

The central target? The concept of achieving “net zero” emissions. It is, after all, at the heart of the UN’s Race to Zero campaign and a central part of the push to limit global temperature rises to 1.5C.

For a business like ours, achieving “net zero” means drastically reducing our greenhouse gas (GHG) emissions, and ensuring that the remaining emissions we add into the atmosphere are no more than the amount we take away. Sounds a simple equation, but delivering it is complex.

After all, few consumers probably realise the incredible journey that goes into bringing Royal Canin to their dog’s food bowl, M&Ms to their corner store, veterinary services to thousands of our clinics or Ben’s Original to their dinner table. Because to truly deliver net zero, we must eliminate or offset GHG emissions across the entire breadth of our value chain – from the farms that provide our ingredients all the way to the end use of our product with consumers.

It is a daunting challenge. But the science is clear and focusing on anything less won’t deliver the impact required.

As we head towards the crucial COP26 UN climate conference in Glasgow next month, we all have a collective responsibility to try to ensure net zero targets – both from countries and businesses – are credible and fit for purpose.

Unfortunately, I can see some serious risks with the recent flurry of net zero announcements. All too often, key components are missing, and that will create a meaningful shortfall in our collective effort to prevent the worst impacts of climate change. So, how do we fill these gaps and put ourselves on a real path to net zero?

First, I believe that any credible net zero claim must cover the associated emissions across the business’s entire GHG footprint, including all scope 3 emissions.

These are emissions for which you have some responsibility, but which might be beyond your control such as emissions from our suppliers or retailers. It means going as far as how consumers use your products. For us, that includes how our products are transported to stores, as well as how consumers use them at home. All too often, these emissions are left out of net zero plans entirely.

I can’t stress how important it is to cover your full value chain, given this is often where the biggest impact of most companies lie. For us at Mars, agriculture and the associated land-use change alone makes up roughly 75% of our emissions footprint. We knew when drawing up our accelerated commitment to achieve net zero by 2050, that addressing that was non-negotiable – no excuses.

Excluding the largest causes of emissions from climate commitments will not drive the critical change needed to tackle climate change and too many of the commitments that have been made are too limited in scope.

The second imperative is combining long-term commitments with acting now to change the trajectory on climate change. We can’t use far-off deadlines as an excuse for inaction and delay.

Within Mars, we are mobilizing our entire business, recognizing that the change we want to see can’t wait decades. We must crack on with the transformation that will help deliver these emissions cuts and hold ourselves to account for meaningful progress along the journey.

It is just a start, but I’m proud that we’ve already managed to cut emissions in our full value chain by 7.3% since 2015 despite our business continuing to grow. In our direct operations, we have already reduced emissions by nearly a third.

But I don’t underestimate the size and complexity of our own commitment to get to net zero across the breadth of our entire supply chain, or what it means for others that have committed to do the same. The old ways of doing business will not deliver the changes required, and it’s clear that a transformational redesign of business supply chains will be critical. This will require a mix of approaches including a shift to renewable energy, stopping deforestation and conversion of natural ecosystems in how we source materials, and embedding climate action at the core of business operations – including tying executive compensation to GHG emission reduction targets. And we can’t achieve our goals without also challenging suppliers to set their own climate targets and take action.

Last, we urgently need an agreed and consistent definition for net zero emissions. Currently, we have something of a free-for-all which allows multiple interpretations.

That doesn’t encourage best practice, nor will it drive the change that the planet requires. As the Science-Based Target Initiative finalizes the first global standard for organizations to commit to and achieve net zero, expected at the end of this year, we hope that it will drive greater alignment and ambition of net zero targets. To be clear, this isn’t about seeking perfection – it’s about progress and our collective success in creating a shared future.

Failing to fill the gaps that exist in some current net zero commitments will undermine their credibility, and even more importantly, the climate action movement.

We can’t allow that to happen.

• Grant Reid is the CEO of Mars