Since the Industrial Revolution in the late 1700s and early 1800s, people have been releasing large quantities of greenhouse gases into the atmosphere. Like other gases in the atmosphere, including oxygen and nitrogen, greenhouse gases are largely transparent to incoming sunlight. Carbon dioxide, the most abundant human-emitted greenhouse gas, has by far the largest climate-warming impact of the long-lived greenhouse gases. This means that after it accumulates in the atmosphere, it is removed relatively quickly – on the timescale of decades in contrast to CO 2 which can persist in the atmosphere … Many greenhouse gases are extremely long-lived in the atmosphere, with some remaining airborne for tens to hundreds of years after being released. Greenhouse gases from human activities are the most significant driver of observed climate change since the mid-20 th century. The greenhouse effect is the way in which heat is trapped close to the surface of the Earth by “greenhouse gases.” These heat-trapping gases can be thought of as a blanket wrapped around the Earth, which keeps it toastier than it would be without them. CO2 is by far the most important long-lived greenhouse gas in the atmosphere related to human activities, and is responsible for roughly two-thirds of the Earth's warming. Greenhouse gas emissions increased 70 percent between 1970 and 2004. These long-lived greenhouse gases become globally mixed in the atmosphere and their concentrations reflect past and recent contributions from emissions sources worldwide. Greenhouse gases include carbon dioxide, methane and nitrous oxides. That amount has skyrocketed in the past century. Amplifying the greenhouse effect. That's why researchers recently released a report evaluating 6 different ways to remove greenhouse gases from the atmosphere, discussing their costs and benefits. Methane is a very ‘short-lived’ greenhouse gas. This graph (source data) shows the combined warming influence of long-lived greenhouse gases as a fraction of their 1990 influence. The table below shows the relative concentrations of these major greenhouse gases and their sources. By December 2019, CO2 in the global atmosphere averaged just over 411 ppm. Even though CO 2 comprises 80% of the greenhouse gases in our atmosphere, it’s like long-sleeved thermal undershirt that might make you feel a little too warm on a hot day, while nitrous oxide is more like an uncomfortable sweater, and fluorinated gases are like that sweltering coat. As shown in Figure 9, CO 2 is the dominant human-influenced greenhouse gas, with a current radiative forcing of 1.46 Wm-2, being 60% of the total from the changes in concentrations of all of the long-lived and globally mixed greenhouse gases. Greenhouse gases in the atmosphere, the main driver of climate change, hit record highs last year and have continued climbing in 2020 despite measures to … 1 The indicators in this chapter characterize emissions of the major greenhouse gases resulting from human activities, the concentrations of these gases in the atmosphere, and how emissions and concentrations have changed over time. How long does methane stay in the atmosphere?