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High El Nino -Southern Oscillation (ENSO) activity in the late 20th century is a footprint of global warming says a recent study. An international team of scientists spearheaded by Jinbao Li and Shang-Ping Xie, while working at the International Pacific Research Center, University of Hawaii at Manoa, has compiled 2,222 tree-ring chronologies of the past seven centuries from both the tropics and mid-latitudes in both hemispheres. Their work is published in the June 30, 2013 online issue of Nature Climate Change . Li, J., S.-P. Xie, E. R. Cook, M. Morales, D. Christie, N. Johnson, F. Chen, R. D'Arrigo, A. Fowler, X. Gou, and K. Fang (2013): El Niño modulations over the past seven centuries. Nature Climate Change . http://dx.doi.org/10.1038/nclimate1936 Caption: This graph shows El Niño variability derived from tree rings (blue) and instrumental measurements (red). The dashed lines indicate boundary for natural variability. Recent El Niño behavior is largely beyo...

Check this latest paper discussing how the influence on Southern Hemisphere climate of the Antarctic ozone hole is slowly dissipating and will be progressively overtaken by human-induced emissions of carbon dioxide and other greenhouse gases... Ozone depletion over the past three to four decades has had a marked impact on Antarctic and Southern Ocean climate.   However, this will shortly be overwhelmed by the influence of greenhouse gases..... discusses this study...... http://www.nature.com/ngeo/journal/v4/n11/full/ngeo1296.html http://www.physorg.com/news/2011-11-greenhouse-gases-overpower-ozone-hole.html NATURE GEOSCIENCE | REVIEW Signatures of the Antarctic ozone hole in Southern Hemisphere surface climate change. David W. J. Thompson, Susan Solomon, Paul J. Kushner, Matthew H. England, Kevin M. Grise & David J. Karoly Nature Geoscience 4, 741–749 (2011) doi:10.1038/ngeo1296

A NASA-led study has documented an unprecedented depletion of Earth's protective ozone layer above the Arctic last winter and spring caused by an unusually prolonged period of extremely low temperatures in the stratosphere. Left: Ozone in Earth's stratosphere at an altitude of approximately 12 miles (20 kilometers) in mid-March 2011, near the peak of the 2011 Arctic ozone loss. Red colors represent high levels of ozone, while purple and grey colors (over the north polar region) represent very small ozone amounts. Right: chlorine monoxide – the primary agent of chemical ozone destruction in the cold polar lower stratosphere – for the same day and altitude. Light blue and green colors represent small amounts of chlorine monoxide, while dark blue and black colors represent very large chlorine monoxide amounts. The white line marks the area within which the chemical ozone destruction took place. Image credit: NASA/JPL-Caltech  published online Sunday, Oct. 2, in the journal...