Alex

Friends of science.

The graph above shows the temperature changes of the lower troposphere from the surface up to about 8 km as determined from the average of two analyses of satellite data. The best fit line from January 2002 to December 2013 indicates a decline of 0.023 Celsius/decade. The sharp temperature spikes in 1998 and 2010 are El Nino events. Surface temperature data is contaminated by the effects of urban development. The Sun's activity, which was increasing through most of the 20th century, has recently become quiet. The magnetic flux from the Sun reached a peak in 1991. The high magnetic flux reduces cloud cover and causes warming. Since then the Sun has become quiet, however it continues to cause warming for about a decade after its peak intensity due to the huge heat capacity of the oceans. So we expect the warming to peak at about 2002. The green line shows the CO2 concentration in the atmosphere, as measured at Mauna Loa, Hawaii. The ripple effect in the CO2 curve is due to the seasonal changes in biomass. There is a far greater land area in the northern hemisphere than the south that is affected by seasons. During the Northern hemisphere summer there is a large uptake of CO2 from plants growing causing a drop in the atmospheric CO2 concentration.

The data are obtained from microwave sounding units (MSUs) on the National Oceanic and Atmospheric Administration's satellites, which relate the intensity or brightness of microwaves emitted by oxygen molecules in the atmosphere to temperature. The MSU data set represent the temperatures of a layer of the atmosphere that extends from the surface to approximately 8 kilometres (5 miles) above the surface. The data is from the University of Alabama in Huntsville and Remote Sensing Systems.

If global warming is real why is the world cooling off.