If the current modern global cooling continues, winters in the Northern Hemisphere and summers in the Southern Hemispere could be colder - human CO2 emissions may actually be irrelevant
(click on images to enlarge)
From 1960 through 2011, over 1 trillion tons of CO2 have been emitted by humans from the burning of fossil fuels. The alarmist global warming theory requires that all those emissions still remain in the atmosphere - per the AGW alarmists, emissions will stay resident in the atmosphere for hundreds to thousands of years.
But as the empirical evidence mounts, those trillions of tons of emissions are having a very small impact on global temperatures - so small, many of the world's best scientists are now questioning the relevancy of human CO2 on the world's climate. The previous modern warming has convincingly morphed into modern global cooling.
The top left chart is a plot of CO2 levels versus global temperatures for December, January and February. These months are typically the coldest for the Northern Hemisphere's winter and warmest for the Southern Hemisphere's summer. As the chart reveals, the last 15 years have seen significant cooling for these three months - including 1998, the trend is a minus 1.3 degrees/century.
The chart on the right, plots the Dec-Jan-Feb temperatures from 1960. The blue shaded areas represent the cooling periods that sandwich the modern warming that ended in 1998 with a kaboom - the Super El Niño of 1998.
Clearly, the massive 1 trillion+ tons of CO2 emissions are not making global temperatures "accelerate" prior to 1977, nor for the post-1998 period.
Conclusions: Modern cooling has prevailed during the December, January and February months since 1998; vast human CO2 emissions are not producing a global warming climate; and, the current cooling phase could switch to warming, or remain as is, depending on natural climatic fluctuations, regardless of CO2.
Note: The above Excel charts plot the simple 3-month average of December, January and February anomalies from the HadCRUT monthly global dataset.