Frequently Asked Questions

Why is it important to reduce carbon emissions quickly?

The burning of fossil fuels has added such a large volume of greenhouse gasses to the atmosphere that it is threatening the livability of the planet. Greenhouse gasses cause the Earth to warm, which in turn causes storms, floods, heat waves, wildfires, and droughts to be more frequent and more extreme.

Carbon dioxide is the dominant greenhouse gas, and its concentration in the atmosphere is rising dramatically. It reached 420 parts per million recently, 50 percent greater than it was prior to the Industrial Revolution (see “The Keeling Curve”).

After carbon dioxide is emitted into the atmosphere, it stays there for 300 to 1,000 years, according to NASA. What we do now—or fail to do—will have impacts for many generations.

Hawai‘i has declared a climate emergency and set a goal to be carbon-negative by 2045. If we are to succeed, we need to reduce our carbon emissions economy-wide; we need a policy that addresses emissions in all sectors.

What is the cost of doing nothing about climate change?

There is a wide range of estimates of the future costs of climate change, but the estimates have one thing in common: they’re all big.

For example, a 2024 study published in Nature projects that the world economy is committed to an income loss of about 19 percent within the next quarter century—or about $38 trillion per year, regardless of the action we take to reduce emissions, and that the cost will steadily increase from there if emissions are not substantially reduced. In comparison, the authors estimated the cost to reduce emissions in accord with the Paris Climate Agreement to be only about $6 trillion per year (in 2050).

A 2022 report from the Deloitte Center for Sustainable Progress indicates that if left unchecked, climate change could cost the global economy $178 trillion over the next 50 years, or a 7.6 percent cut to global gross domestic product (GDP) in the year 2070 alone. If global warming reaches around 3°C toward the century’s end, the toll on human lives could be significant. It would disproportionately impact the most vulnerable, and lead to loss of productivity and employment, food and water scarcity, worsening health and well-being, and usher in an overall lower standard of living globally. By contrast, the global economy could gain $43 trillion over the next five decades by rapidly accelerating the transition to net-zero carbon emissions.

A 2024 report commissioned by Consumer Reports and conducted by ICF, a global consulting firm that conducts climate studies for businesses and governments, might snap some of us to attention. Its finding: If humanity does not act swiftly to limit climate change, it will cost a typical child born in 2024 at least around $500,000 over the course of their lifetime—and possibly as much as $1 million—through a combination of cost-of-living increases and reduced earnings.

For Hawai‘i, specifically, no study has been made of all the expected costs of climate change, but a 2017 study by the Hawaiʻi Climate Change Mitigation and Adaptation Commission examined some of the costs stemming from sea level rise. The Hawai‘i State Legislature cited the sea level rise study when, in 2019, it authorized a study of carbon pricing in Hawai‘i. It stated, “Climate change is expected to cost the State at least $19 billion in losses from sea level rise alone, making the switch to renewable energy and the ultimate reduction of atmospheric carbon a priority.”

The Keeling Curve

How Does Carbon Cashback Work?

Why Carbon Cashback in Hawai’i?

How would Carbon Cashback Impact Hawai’i?

How Does Carbon Cashback Relate to other Climate and Energy Policies?

Carbon Cashback - In One Page and One Minute