Naomi Steinberger’s April 19 letter that “questions global warming” ignores the fact that about 97 percent of climate experts and all science academies worldwide believe that climate change is happening, is largely caused by human activities, and poses a severe threat to humanity. Virtually all published articles that consider the issue in respected refereed scientific journals agree with this conclusion.

Ms. Steinberg’s statement that temperatures recently have been flat ignores that 2012 was the warmest year in the continental U.S. and that the 11 warmest years worldwide since temperature records have been kept in 1880 have occurred since 1998.

At a time when polar ice caps and glaciers all over the world are rapidly melting, when there has been an increase in the number and severity of heat waves, droughts, wildfires, storms, and floods, and when climate scientists are warning that we may reach a tipping point when climate changes spin out of control, Ms. Steinberg’s letter has the potential of continuing the apathy, denial, and misinformation that can prevent the necessary actions that can help shift our imperiled planet onto a sustainable path.