Alpha particles, beta particles, gamma rays, muons, neutrinos: The list is long and puzzling, and most of it has nothing to do with human activities. (discovermagazine.com)
Other scientists believe that global warming is a natural process that has nothing to do with human activity. (globalwarmingsolved.com)
There is a hard core of these who will die believing that it is not happening or that it is «normal» or that it is nothing to do with human activity. (ramblingsdc.net)