I generally find articles by Jerusalem Post op-ed editor Seth Frantzman to be well-reasoned, insightful and informative. So I was disappointed and saddened to read his April 25 article, “Plan for, don’t gripe about, climate change,” in which he argues that we should accept and plan to deal with climate change by, for example, planning “for ocean levels rising several inches,” instead of “trying to ‘defeat’ it.”Unfortunately, climate change is an existential threat to Israel and, indeed, to the whole world, with ocean levels potentially rising many feet, and averting a global climate catastrophe must become a major focus for civilization today.An outrageous exaggeration? Not according to science academies worldwide, 97% of climate scientists and virtually all peer-reviewed papers on the issue in respected scientific journals, that argue that climate change is largely caused by human activities and poses great threats to humanity. All the leaders of the 195 nations at the December 2015 Paris Climate Change conference, including Israel, agreed that immediate steps must be taken to combat climate change. The Pentagon and other military groups believe that climate change will increase the potential for instability, terrorism and war by reducing access to food and clean water and by causing tens of millions of desperate refuges to flee from droughts, wildfire, floods, storms and more.The world is already seeing the effects of climate change. Contrary to the views of many climate-change deniers, the world’s temperature has significantly increased in recent years. Every decade since at least the 1970s has been warmer than the previous decade and all of the 17 warmest years since temperature records started being kept in 1880 have been since 1998. 2016 was the warmest year globally, breaking the record held previously by 2015 and before that by 2014, the first time that there have been three consecutive years of record temperatures.Just as a person with a high fever suffers from many of its effects, there have been many negative effects of the increased global temperature. Polar icecaps and glaciers worldwide have been melting rapidly, faster than scientific projections. This has caused an increase in ocean levels worldwide with the potential for major flooding. Already some coastal cities, including Miami, Florida, are experiencing “sunny day flooding,” due to high tides. Glaciers are “reservoirs in the sky,” providing important water for irrigating cops every spring, so their retreat will be a major threat to future food supplies for an increasing world population.There has also been an increase in the number and severity of droughts, wildfires, storms and floods. California has been subjected to so many severe climate events recently that its governor, Jerry Brown, stated that “humanity is on a collision course with nature.”Unfortunately, prospects for the future are truly terrifying. Many climate experts believe that we are close to a tipping point where climate change will spiral out of control, with disastrous consequences, unless major positive changes soon occur.All the severe climate events that have occurred so far have occurred due to an average world temperature increase of only one degree Celsius since the start of the industrial revolution. While climate scientists hope that the total temperature increase can be limited to two degrees Celsius, largely because that is the best that can be hoped for with current trends and momentum, the world is now on track for an average increase of at least four degrees Celsius, which would produce a world with almost unimaginably negative climate events.Another alarming factor is that, while climate experts believe that 350 parts per million (ppm) of atmospheric CO2 is a threshold value for climate stability, the world has now reached 414 ppm, and the CO2 level is increasing by at least 3 ppm per year.Many people believe that climate change has become a political issue, mainly promoted by liberals like Al Gore. However, the conservative group ConservAmerica (www.ConservAmerica.org), formerly known as “Republicans for Environmental Protection,” is very concerned about climate change threats. They are working to end the denial about climate threats and the urgency of working to avert them on the part of the majority of conservatives, but so far with very limited success.Given the above, averting a potential climate catastrophe should be a central focus of civilization today, in order to leave a liveable world for future generations. Every aspect of life should be considered. The world has to shift to renewable forms of energy, improve our transportation systems, produce more efficient cars and other means of transportation, produce far less meat and other animal-based foods, and do everything else possible to reduce greenhouse gas emissions (GHGs).As president emeritus of Jewish Veg, formerly Jewish Vegetarians of North America, I want to stress the generally unknown or disregarded importance of shifts toward vegan diets. Animal- based agriculture its a major contributor to climate change, largely due to the emission of methane from cows and other farmed animals, since methane is from 72 to 105 times as potent as CO2 per molecule in warming the atmosphere, during the 20 years that the gas is in the atmosphere.Two studies support this conclusion: 1. A 2006 UN Food and Agriculture Organization study, “Livestock’s Long Shadow,” found that livestock agriculture emitted more GHGs, in CO2 equivalents, than all the cars, planes, ships and other means of transportation worldwide combined.2. A 2009 front-page story in World Watch magazine, “Livestock and Climate Change,” by two environmentalists associated with the World Bank, found that the livestock sector was responsible for at least 51% of all human-induced GHGs.So, a major shift away from animal-based diets is essential to efforts to avert a climate catastrophe.Because the threats are so great, it is essential that everyone make this issue a major priority, and make every effort to make dietary and other lifestyle changes, in order to help shift our imperiled planet onto a sustainable path. Unfortunately, “denial is not just a river in Egypt,” and most people today are, in effect, rearranging the deck chairs on the Titanic, as we head toward a giant iceberg.When I hear of a baby being born, I wonder how his or her life will be affected by our rapidly warming world, with its rising oceans and increasingly severe storms. This is especially relevant to me as I write this as I have a granddaughter who recently married and a grandson who is planning a wedding with his fiancée.The Jerusalem Post would do a great public service by using its excellent writers and editors to help increase awareness of the seriousness of climate threats and the steps necessary to help avert a climate catastrophe.The author is Professor Emeritus at the College of Staten Island.