Planet Earth's current warming trend is based largely on natural warming and cooling cycles that have been happening for eons; as well as human-caused additions to greenhouse gases, which are boosting the atmosphere's ability to trap heat in the biosphere. Minor factors like an overall increase in the sun's solar intensity play a smaller role.

While greenhouse gases are an essential component of a livable planetthey're what keep Earth from being a lifeless ball of icehumans are causing greenhouse gas levels to increase so quickly that it's causing the average global temperature to rise much faster than it would naturally.

It's worth remembering that global warming is based on an increasing average global temperature. Some parts of the planet (such as the Arctic) are getting warmer much faster than other areas. It's even possible that some regions could actually experience regional cooling at the same time the planet as a whole is experiencing global warming. Here's how.

The "thermohaline circulation" in the world's oceans is part of the planet's temperature regulation system. It can warm or cool regional climates to make their average temperatures different that they would be normally based on their latitude.

The most notable example of this is how the Gulf Stream brings warm water up from the tropics to make Europe much warmer than it would be naturally. This part of the thermohaline circulation is dependent on regular additions of fresh water from melting Arctic ice (which is replaced every year through additional snowfall). If the flow of fresh Arctic water decreases enough, it could slow or even stop the thermohaline circulation, leading to cooler temperatures in Europeeven at the same time other areas are experiencing severe temperature increases.

There's more than one offender in the crime of laying waste to the planet's old growth forests for inappropriate purposes, but one the biggest is Kimberly-Clark, the largest tissue-products company in the world, with sales in 150 countries. Some of the Kimberly-Clark brands of disposable paper products you're likely to see on supermarket shelves are Kleenex Facial Tissues, Scott Toilet Paper and Paper Towels, Cottonelle Toilet Paper, and Viva Paper Towels. The company also sells toilet paper and tissues to large institutions like universities, high schools, governments, and businesses. In North America, only about 1/5 of the pulp that Kimberly-Clark uses for its disposable tissue products comes from recycled sources, and most of that goes into the products that go to large institutions, not consumers.

In 2004, Greenpeace and the Natural Resources Defense Council set their sights on Kimberly-Clark's practice of sacrificing virgin forests at the Altar of Blowing and Wiping, particularly as the practice applies to Canada's ancient Boreal forests. The goal of their "Kleercut" campaign is to get consumers involved in pressuring Kimberly-Clark to stop this unnecessary, wasteful practice.

Now, just in case your germ-a-phobic subconscious is wondering whether recycled paper is really clean enough to be used in paper products destined for such personal purposes, yes it is. The process that takes recycled-paper pulp and turns it into soft, perfect little pieces of napkin, paper towel, toilet paper, or facial tissue also ensures that the products are sanitary.

So, what brands can you buy with a clear conscience? The table below lists the top "green" brands and provides statistics on their use of recycled paper and what portion of the recycled paper is post-consumer content (PCC)i.e. what portion of the recycled paper comes from people's recycle bins. It's also worth noting that the top four brands we list are all free of chlorine bleach, which is another environmental problem.