If you're in charge of a major metropolitan city, it's almost a must these days to be sustainable. Us city dwellers pride ourselves on living in places that are taking action on climate change and achieving net zero. But what if you're Don Iveson? You're the mayor of oil and gas town Edmonton, in northern Alberta, Canada. Or across the Atlantic, Holly Mumby-Croft, UK member of parliament for Scunthorpe, home to one of the last steel plants of Britain. Or much smaller, you're Dave Smiglewski. You're the mayor of the little city of Granite Falls, Minnesota, with a large-scale ethanol production facility nearby. All these places, no matter how far apart and how different in size, have something big in common: millions of tons of greenhouse gas emissions linked to significant local employment. And we're going to have to find a way to maintain the critical economic and social functions of these towns if we're to have any hope of combating climate change. Not an easy feat, if you think that we can't really put a solar panel on a gas processing facility or a steel mill. Fortunately, these places have another interesting thing in common, which might offer some hope to these local officials. The main sources of pollution in their areas are in close proximity to rock formations with the ability to trap carbon dioxide, the greenhouse gas we often call CO2. And this puts into reach a potential solution to both their problems: pollution and employment. It's called "carbon capture and storage." It's the process whereby we capture the CO2, which results from burning fossil fuels, before it's emitted into the atmosphere and instead bury it underground. Effectively, we take part of what we've extracted from the earth -- the carbon -- back to where it came from. Now, this is not a new idea. People have been experimenting with this technology for decades. Today, however, there are very few operational carbon capture facilities in the world, capturing about 14 million tons of CO2 equivalent per year. And while that may sound like a big number, it's less than .1 percent of global greenhouse gas emissions. The International Energy Agency predicts that we need to capture between four and seven gigatons -- that's four to seven billion metric tons -- of CO2 per year by 2040 to stay at or below two degrees Celsius warming. And that's a more than 100 to 200 times increase in today's carbon capture capacity. To get us there will definitely require a price on greenhouse gas pollution. There is a cost, and it needs to be settled. And if we're not smart about it, the price could be very high. Should we then solely rely on the future improvements in the fundamental technology? No. There is another way. And it's the need for well-thought-through rollouts of what might be called CO2 networks. In BCG, I lead a team of consultants, analysts and data scientists whose focus is on advancing carbon capture utilization and storage. By our estimates, if we want to hit the IEA forecast, we need at least 110 billion dollars per year for the next 20 years to build out the required carbon capture and storage infrastructure. And there's only one way to bring down this essential but hefty price tag, which is to share the cost through networks. Consider it the waste disposal service for CO2. Our research suggests that policymakers and companies can learn a lot by looking at a map -- lots of maps, actually, both the ones that you and I look at on our smartphones as well as the less common ones that show what lies below the surface in terms of depleted oil and gas fields and saline aquifers with the ability to trap CO2 underground. And by looking at these maps, we can look for the optimal distances between both the sources of emissions, like Scunthorpe's steel plant, and the sinks, like the saline aquifers of Alberta. We had a first go, and it yields interesting results. By building up a detailed database of emitters as well as potential sinks, we found up to 200 clusters that have the ability to be scaled up to low-cost carbon networks. And they can capture more than one gigaton of emissions, a big step to the four to seven gigatons that we need. And when we dig a little deeper, we find that optimization of distances between sinks and sources matters. It matters a lot in terms of the cost. Network effects, which is the mechanism whereby the benefits of a system to a user increases with the amount of others' use of it, can reduce the capture and storage cost of many emitters by up a third, to below 100 dollars per ton of CO2 captured, based on current costs of technology. And while that is still a substantial cost, it starts to get in the range of carbon taxes and market mechanisms that governments of Western economies are starting to think about or have already put in place. And we would not be able to achieve it without collaboration and sharing of infrastructure between neighboring emitters. Let us walk through some of the cities I mentioned. In assessing areas to build CO2 networks, we look for three different things. Firstly, proximity to storage. Secondly, a cluster of at least a few sources with high amounts of CO2 in their flue gas; the more CO2 in the exhaust, the cheaper it is to capture. And thirdly, an ability to scale up the network and lower the cost quickly with few emitters. Edmonton and its surrounding areas provide a good example of this idea at work. Suitable underground rock layers that can trap CO2 are abundant, well exceeding what is needed, and it also meets the second and third criteria in that it has a good combination of both high- and low- concentration CO2 streams associated with different industrial processes. And it can scale up to low cost quickly. In one of the clusters, we find the number of emitters with very low capture and storage cost in the range of 40 to 50 dollars per ton, but they only represent 1.2 megatons per year. The total cluster, however, can scale up to 12 megatons -- up to 10 times its original size. But those first megatons of emissions played a crucial role in scaling up the network and reducing the cost and risk for others down the line. That's your network effect in action. And it's not just Edmonton. If we take Scunthorpe in Lincolnshire in the UK, we see similar dynamics and potential. The North Sea offers sufficient storage, and while storing CO2 offshore is more expensive than onshore, there's the potential to reduce this cost by reusing and repurposing existing oil and gas infrastructure. If the steel mill standalone would have to capture and store its CO2, it would prove very costly. But it can reduce this cost by sharing the infrastructure with refining and chemical emitters en route to the North Sea. Many of them have cheaper capture cost with the ability to improve the overall economics and kick-start a network that has the ability to scale up to 28 megatons. Two examples in two different countries with 14 megatons of potential -- already double versus what we have today. And this network effect applies anywhere and is actually not uncommon when it comes to building out infrastructure. In fact, CO2 networks could very much follow the principles of the past in terms of how our energy and utility infrastructure was developed around us, whether it's water, gas, electricity, local supply chains -- all these networks apply local economies of scale and were built up over time with favorable, marginal cost of adding new connections. The big difference here is we're reversing the flow. And these networks have the potential to enable future innovation of using CO2 in chemical processes to make, for example, building materials instead of burying the CO2 underground. Our analysis is a pure economic one. It does not account for political and local geographical barriers, but creating a favorable regulatory environment and removing these barriers will be critical. Take these two neighboring states in the US, for example: North Dakota, with ample, cheap storage and existing CO2 pipelines, and the state has put in place tax incentives and financial assistance to use it. Go next door to Minnesota: no storage within several hundred miles, but home to 18 large-scale ethanol production facilities, including the one in Granite Falls, all of which create a highly concentrated stream of CO2 emissions. Can the blue and the red state work together to add 40 megatons to our carbon capture tally? We have no more than 20 years to bend the curve and combat climate change -- potentially less. The gas networks in my two home countries of the Netherlands and the UK were built in similar time frames after the Second World War -- massive undertakings in infrastructure buildup and at a time of similar high national debt. It's time to build another network, one for CO2. It does not need to last forever. It can be there just for the transition away from fossil fuels. But we need it now to preserve local manufacturing jobs and our communities and provide a hope for a better and more sustainable future. It is critical that governments, both local and national, as well as companies, assess the potential for carbon capture at a local level, start to capture the cheapest sources of CO2 and build up the network from there. Only in that way can local communities like the ones in Edmonton, Granite Falls, Scunthorpe and beyond thrive both economically and sustainably. Thank you.