What was the total amount of capital expenditures (capex) deployed by the company in 2021 
rades in multiple markets, including nearly $105 billion spent by U.S.
carriers for critical mid-band spectrum and over $65 billion in capex deployed by carriers into network investments across our global footprint. With mobile data consumption expected to grow at an average annual rate of more than 25% over the next five years in the United States and at even higher rates in some of our international markets, we anticipate prolonged network investment cycles to drive compelling, sustained growth rates across our regions. And while we believe our macro tower assets will continue to drive the vast majority of growth and returns for the company as 5G advances, we're also excited about additional opportunities that we expect to arise from the accelerating cloud-based interconnected and globally distributed digital transformation that is in its early stages today. We expect our recently closed CoreSite acquisition to augment our ability to capture potential upside from this transformation while enhancing the value of our existing portfolio of distributed communications real estate over time.
We anticipate these expectations to be underpinned by the continued execution of the four strategic pillars in our Stand and Deliver strategy, growing our assets and capabilities, driving industry leadership, operational efficiency, and extending our platform. As part of our commitment to growing our assets and capabilities to meet our customers' needs, we deployed more than $10 billion for tower M&A in 2021 focused on Europe, where we have meaningfully improved our long-term strategic positioning. We saw accelerated organic growth trends in the region throughout the last year, and we expect those trends to continue, supported by data growth projected at a CAGR of 26% over the next five years across our major European markets. Separately, we added strategic financial partners, CDPQ and Alliant, who joined our existing partner, PGGM, creating a solid platform for future growth and investment ahead of what we anticipate being an exciting decade in the European marketplace.
In addition to expanding through M&A, we further grew our asset base through our internal capex program by investing $1.4 billion, primarily to construct a record of nearly 6,400 new communication sites, along with deploying nearly $120 million toward our energy efficiency investments, primarily in Africa. These investments continue to generate returns that are among the highest in our portfolio. Through our talented teams and operational expertise, we expect to remain a preferred partner to support customers as they execute on their network build-outs, which we expect to drive continued acceleration in our new site construction for the next several years while advancing our sustainability efforts and commitment to a greener mobile future. Through our commitment to enhance our industry leadership, we've continued our focus on sustainability by accelerating our efforts to combat climate change, as evidenced by our recent adoption of science-based targets for carbon emission reductions.
These targets represent direct and indirect greenhouse gas emissions reduction targets of at least 40% by 2035 against the 2019 baseline, as well as targets to reduce indirect supply chain emissions by at least 40%. To date, we've invested over $275 million in capex toward energy efficiency and reduction solutions, which directly support our committed targets and initiatives. Concurrent with our emissions reduction targets and renewable energy investments, we are actively working on various land stewardship and social impact initiatives. We're a member of the World Economic Forum's Edison Alliance 1 Billion Lives Challenge, which aims to spur development of affordable and accessible digital solutions across health, finance, and education to the underserved.
Through our involvement, we engaged with an array of high-level country and regional platforms and committed our time, expertise, and ideas to make digital access a top priority for all. Also this past year, American Tower was awarded a 
rades in multiple markets, including nearly $105 billion spent by U.S.
carriers for critical mid-band spectrum and over $65 billion in capex deployed by carriers into network investments across our global footprint. With mobile data consumption expected to grow at an average annual rate of more than 25% over the next five years in the United States and at even higher rates in some of our international markets, we anticipate prolonged network investment cycles to drive compelling, sustained growth rates across our regions. And while we believe our macro tower assets will continue to drive the vast majority of growth and returns for the company as 5G advances, we're also excited about additional opportunities that we expect to arise from the accelerating cloud-based interconnected and globally distributed digital transformation that is in its early stages today. We expect our recently closed CoreSite acquisition to augment our ability to capture potential upside from this transformation while enhancing the value of our existing portfolio of distributed communications real estate over time.
We anticipate these expectations to be underpinned by the continued execution of the four strategic pillars in our Stand and Deliver strategy, growing our assets and capabilities, driving industry leadership, operational efficiency, and extending our platform. As part of our commitment to growing our assets and capabilities to meet our customers' needs, we deployed more than $10 billion for tower M&A in 2021 focused on Europe, where we have meaningfully improved our long-term strategic positioning. We saw accelerated organic growth trends in the region throughout the last year, and we expect those trends to continue, supported by data growth projected at a CAGR of 26% over the next five years across our major European markets. Separately, we added strategic financial partners, CDPQ and Alliant, who joined our existing partner, PGGM, creating a solid platform for future growth and investment ahead of what we anticipate being an exciting decade in the European marketplace.
 In addition to expanding through M&A, we further grew our asset base through our internal capex program by investing $1.4 billion, primarily to construct a record of nearly 6,400 new communication sites, along with deploying nearly $120 million toward our energy efficiency investments, primarily in Africa. These investments continue to generate returns that are among the highest in our portfolio. Through our talented teams and operational expertise, we expect to remain a preferred partner to support customers as they execute on their network build-outs, which we expect to drive continued acceleration in our new site construction for the next several years while advancing our sustainability efforts and commitment to a greener mobile future. Through our commitment to enhance our industry leadership, we've continued our focus on sustainability by accelerating our efforts to combat climate change, as evidenced by our recent adoption of science-based targets for carbon emission reductions.
These targets represent direct and indirect greenhouse gas emissions reduction targets of at least 40% by 2035 against the 2019 baseline, as well as targets to reduce indirect supply chain emissions by at least 40%. To date, we've invested over $275 million in capex toward energy efficiency and reduction solutions, which directly support our committed targets and initiatives. Concurrent with our emissions reduction targets and renewable energy investments, we are actively working on various land stewardship and social impact initiatives. We're a member of the World Economic Forum's Edison Alliance 1 Billion Lives Challenge, which aims to spur development of affordable and accessible digital solutions across health, finance, and education to the underserved.
Through our involvement, we engaged with an array of high-level country and regional platforms and committed our time, expertise, and ideas to make digital access a top priority for all. Also this past year, American Tower was awarded a 