
Saki (H.H Munro) said, "A little inaccuracy sometimes saves tons of  explanation." Today we have tons of inaccuracy and very little explanation. Most  inaccuracies come from claims based on non-existent or inadequate historical  data, extremely crude estimates, computer model projections, or are simply  incorrect. It's prevalent in environmental issues but particularly bad with  climate and animal extinctions. The reason is because they're the most  politicized, which automatically takes them further from the truth. As Henry  Adams said, "Practical politics consists of ignoring the  truth."
Speculative and Theoretical Nonsense
A good example is a  2008 report that claimed, "Human activity is wiping out close to one per cent of  every other species on Earth every year, a global environmental report said  Friday." What absolute rubbish. They can't possibly substantiate these claims.  We don't know how many species there are. We are finding new species all the  time. We don't have even crude estimates of populations. We don't know how much  population numbers vary. What do they mean by "every other"? They should name  all the species that comprise their claims? 
Numbers in the 2008 Report  are part of the ridiculous, completely unscientific, claims made originally by  E.O. Wilson about species extinction. Self-proclaimed Canadian environmentalist  David Suzuki traveled across the country a few years ago claiming the demise of  2 species an hour. He wouldn't name any of them because it's a false claim. It  undoubtedly originated with E.O Wilson, who is listed as an honorary Board  member of the Suzuki Foundation in the 2003 Annual Report.
Wilson  introduced his idea of extinction based on mathematical estimates and false  assumptions. "A good proxy for the rate of extinction is the rate of growth in  energy used by the human population. In other words, extinction rates are  increasing in step with the product of population growth times the growth in  affluence."
Wilson's actual extinction claim was 27,000 per year. He also  predicted 22 percent of all species will be extinct by 2022. It's time the media  provided a daily obituary column with names of the 48 species provided by the  Suzuki Foundation. It won't happen because they don't exist, but that won't stop  others making false claims.
Claims of declining numbers work because  we're emotionally vulnerable to charges we're negatively impacting animal  populations. They work because people believe populations don't change much  naturally therefore large or sudden changes are due to humans.
They works  because the Intergovernmental Panel on Climate Change (IPCC) made a statement in  their 2007 Impact Report that "Global-scale assessment of observed changes shows  that it is likely that anthropogenic warming over the last three decades has had  a discernible influence on many physical and biological systems."
This is  out of context and unsupportable. The word "likely" is defined as a 66 to 90%  probability, which undercuts the certainty of the statement. It's out of context  because you can't determine the human effect without knowing or understanding  natural change. This is the major problem with the IPCC Science Report on  climate so it is not surprising to see it repeated in the Impact Report.