Will I have to work on Saturdays? <a href=" http://www.ottieandthebea.com/buy-xenical-cheapest.pdf ">buy xenical cheap online</a> What causes decadal changes in the rate of warming? IPCC lead author Professor Steve Sherwood, from the University of NSW, says there are no definitive answers, but points to changes in the uptake of heat in the oceans as one factor. Others include changes in atmospheric aerosol concentrations and solar activity. Sherwood likens decadal changes in warming rates to a cancer sufferer. While they may feel a little better one week compared with the next, it does not mean they are rid of the disease.