Nuclear energy contributes a very small amount of emissions into the atmosphere which can cause many environmental problems such as global warming. Uranium is not burned in a nuclear power plant as coal is so there are no emissions from it.
Info on the 2017 USPS Postage Rate Increase. The U.S. Postal Service (USPS) will implement new postage rates for several mailing and shipping products on Sunday, January 22, 2017. Summary of the 2017 Postage Rate Increase: First Class Mail Letters (1 oz.) rates will increase from $0.47 to $0.49 when purchased at the Post Office. Each additional ounce will cost $0.21.
Re: Using stamps - getting the amount correct with new stamps? The Forever stamp is always going to be worth whatever the current postage rate for 1 ounce is. So even you bought it for 46 cents it is now worth 49 cents of postage. I always have a small supply of add on stamps that I can attach for oversize, overweight, second ounce, etc. letters.