The Fourth of July holiday weekend is a time when Americans indulge in the excesses of carbon: extra charcoal on the barbecue for family and friends, extra gas for a holiday trip in the family minivan, and extra electricity for the air conditioning at night. It’s all part of the great American pastime — using carbon molecules. We love it.

Yet on July 9 world leaders will meet at a Group of Eight summit in Hokkaido, Japan, to discuss halving global greenhouse gas emissions, primarily carbon, by 2050.

Released CO2 gas makes the atmosphere more like a greenhouse, or it gets absorbed by the oceans and acidifies them. It’s not that the world faces a shortage of oil and gas. Rather, the problem is that there may be no longer enough buffering capacity in the seas and the sky to hide the results of CO2 released by man and protect us from the consequences.

Cuts in carbon are proposed because scientists report that it causes global warming and adversely affects the earth’s climate. But some scientists, including Nobel Prize winning atmospheric chemist Paul Crutzen, now believe that altering features of the Earth’s environment would be more effective and efficient against stopping global warming. This is called “geoengineering.”

Advocates of geoengineering suggest it as a complement to reduce the use of carbon as a way to prevent or retard global warming. Examples of geoengineering include injecting fine sulfur particles into the upper atmosphere to slow down the warming process from the sun, and spraying clouds with salt water to increase their reflectance. Clouds would reflect more heat back toward the sun, away from Earth. Cooling effects — as well as other adverse consequences — have been observed after volcanic eruptions.

Successful geoengineering would permit Earth’s population to make far smaller reductions in carbon use and still achieve the same retarding effect on global warming at a lower cost.

The cuts in carbon use proposed by international leaders and presidential candidates would have a drastic effect on the economy, especially since substitutes for fossil fuels will be expensive and limited for a number of years.

In a June 24 speech in Virginia, Senator McCain announced his plans for carbon emissions: “By the year 2012, we will seek a return to 2005 levels of emission, by 2020, a return to 1990 levels, and so on until we have achieved at least a reduction of sixty percent below 1990 levels by the year 2050. In this way, we will transition into a low carbon energy future while staying on a course of economic growth.”

Senator Obama believes that climate change is “one of the greatest moral challenges of our generation,” according to a speech in Iowa last fall. That’s why he wants levels of carbon emissions to be 80% lower in 2050 than in 1990, not just Mr. McCain’s 60%.

For both candidates that’s change you simply have to believe in: A means of cutting carbon emissions from 1990 levels by 60% or 80% by 2050 has not been invented, unless they envision a smaller population or lower standard of living.

A scientist at the National Center for Atmospheric Research, Thomas Wigley, observes that the rate of development of new carbon-neutral technologies is likely to be so slow that reducing carbon as fast as we can may not suffice to avoid harmful consequences of climate change.

Further, if India and China don’t also sign up to cut their carbon emissions — and they haven’t committed to reductions under the Kyoto Protocol — these proposed dramatic cuts in American carbon emissions alone would not solve the problems of climate change. American emissions would just be replaced by emissions from others.

Hence scientists’ new curiosity about geoengineering merits widespread attention. Even if other countries did nothing, successful geoengineering would have global effects on climate change and largely eliminate the regulatory burden of monitoring and enforcing compliance.

A combination of geoengineering and carbon reduction could succeed in eliminating warming and keeping the sea levels from rising.

The science behind geoengineering is too early for venture capital and private markets to support it, and protecting us from outside dangers such as war and global climate change is a core government function. So it is astonishing how little federal funding is available for geoengineering research.

Hundreds of millions of dollars are committed to research and development on alternative energy technologies, and trillions may be imposed as taxes on carbon emissions. Yet geoengineering, which could obviate the majority of the need for carbon cuts and enable us to avoid lifestyle changes, gets a tiny sum.

This needs to change. Researchers should be empowered with funding to figure out what geoengineering can and cannot do, so the most effective and efficient tools to tackle climate change can be made available sooner. We don’t know what 2050 will bring, but we hope that we’ll still be able to celebrate the Fourth with barbecues and holiday trips.

Ms. Furchtgott-Roth, former chief economist at the U.S. Department of Labor, is a senior fellow at the Hudson Institute.