sheets. "Emissions of black carbon are the second strongest contribution to current global warming, after carbon dioxide emissions". Calculation of black carbon's combined climate forcing at 1.0–1.2 W/m2, which "is as much as 55% of the CO2 forcing and is larger than the forcing due to the other [GHGs] such as CH4, CFCs, N2O or tropospheric ozone." Other scientists estimate the total magnitude of black carbon's forcing between + 0.2 and 1.1 W/m2 with varying ranges due to uncertainties. (See Table 1.) This compares with the IPCC's climate forcing estimates of 1.66 W/m2 for CO2 and 0.48 W/m2 for CH4. (See Table 2.) In addition, black carbon forcing is two to three times as effective in raising temperatures in the Northern Hemisphere and the Arctic than equivalent forcing values of CO2. Jacobson calculates that reducing fossil fuel and biofuel soot particles would eliminate about 40% of the net observed global warming. (See Figure 1.) In addition to black carbon, fossil fuel and biofuel soot contain aerosols and particulate matter that cool the planet by reflecting the sun's radiation away from the Earth. When the aerosols and particulate matter are accounted for, fossil fuel and biofuel soot are increasing temperatures by about 0.35 °C. Black carbon alone is estimated to have a 20-year Global Warming Potential (GWP) of 4,470, and a 100-year GWP of 1,055–2,240. Fossil fuel soot, as a result of mixing with cooling aerosols and particulate matter, has a lower 20-year GWP of 2,530, and a 100-year GWP of 840–1,280. The Integrated Assessment of Black Carbon and Tropospheric Ozone published in 2011 by the United Nations Environment Programme and World Meteorological Organization calculates that cutting black carbon, along with tropospheric ozone and its precursor, methane, can reduce the rate of global warming by half and the rate of warming in the Arctic by two-thirds, in combination with CO2 cuts. By trimming "peak warming", such cuts can keep current global temperature rise below 1.5 ˚C for 30 years and below 2 ˚C for 60 years, in combination with CO2 cuts. (FN: UNEP-WMO 2011.) See Table 1, on page 9 of the UNEP-WMO report. The reduction of CO2 as well as SLCFs could keep global temperature rise under 1.5 ˚C through 2030, and below 2 ˚C through 2070, assuming CO2 is also cut. See the graph on page 12 of the UNEP-WMO report. Control technologies Ramanathan notes that "developed nations have