Debunking myths around the climate crisis
Watch: Newshub Nation explores what New Zealanders will have to change and when to limit global warming to 1.5 degrees. Credits: Image - Getty; Video - Newshub Nation. This is false. At least 95 percent of scientists in the field believe there is sufficient evidence to support the existence of climate change caused largely by human activities, so-called "anthropogenic global warming". The consensus is mainly channelled through the Intergovernmental Panel on Climate Change (IPCC), the main international body for the evaluation of the phenomenon, set up in 1988 by the United Nations Environment Program and the World Meteorological Organisation, of which 195 countries are members. In their most recent report published in September, more than 100 scientists warned of the urgent need to reduce greenhouse gas emissions to limit the magnitude of changes to oceans and ice sheets. The effects of the earth's natural cycles have nothing to do with the global warming recorded in the last century. The three natural causes of climate variability are sunspots, an indicator whose periodicity is about 11 years; changes in the earth's orbital cycles, which operate on scales of thousands or hundreds of thousands of years; and volcanic eruptions. "Since there is an instrumental registry, more than 100 years ago, none of the three natural causes explain global warming and the patterns are completely different," said Fernando Valladares, a researcher on the Higher Council for Scientific Research. Sunspots are indicative of changes in the sun's activity that occur every decade and are not related to rising temperatures in the past 60 or 70 years. The Fifth Assessment Report of the IPCC, published in 2014, contributed to the falsity that global warming was interrupted in 1998, which stated that the average temperature had shown a linear trend of a smaller increase in the last 15 years (1998-2012) than in the 30-60 previous. But warming has not stopped at all. In fact, the average global temperature for the years 2015-2019 is on its way to being the warmest of any other registered equivalent period, one degree Celsius above pre-industrial times (1850-1900). This year will be among the five warmest ever due to climate change, according to WMO data. Sanz recalled that in 1998 there was a rise of almost 0.7C due to the El Nino weather phenomenon, but the general trend can only be measured with long historical series and reveals that the average temperature continues to rise. Valladares pointed out that the warmest four years of the past 150 were in the last decade. Moreno said 2018 was the fourth warmest year since records began. Warming favours business opportunities in some sectors and can even improve the health of those who live in the mountains or north of the 50th parallel, but the population benefited would be less than 5 percent of the total, Valladares said. The result is negative for humanity and, as Sanz warned, the increase in extreme phenomena will generate numerous economic outcomes and losses to human life. In the past 25 years, the sea level has risen an average of 8 centimetres (in some areas, more than 20cm). Climate change will also raise the risk of fires, cyclones and large droughts, trigger the salinisation of aquifers near coasts, reduce water availability, hinder the conservation of cold in industrial food facilities and threaten the electricity supply in large cities. The ozone layer protects life on earth from the sun's ultraviolet rays but warming is not caused by the direct effect of solar radiation, but by infrared radiation reflected by the planet and trapped by greenhouse gases, primarily CO2. The concentration of CO2 reached a record of 407.8 parts per million (ppm) last year, which could be even higher in 2019. To understand the dimension of the problem, the last time a concentration of 400ppm was recorded was more than 3 million years ago, when the global temperature was two or three degrees higher than the current one. AAP