Climate Change Basics Steven Mamet Department of Biology University of Saskatchewan LeeAnn Fishback Scientific Coordinator Churchill Northern Studies Centre The last 125 years Global warming is now 0.8 C in the past three decades and 1.2 C in the past century. Where do scientists measure temperature to get a global average? IPCC 2013 How does the average global temperature of the past 200 years compare with the previous 2000? IPCC 2013 The last 2000 years. Could other things be causing the earths temperature to rise? Not due to solar output increase IPCC 2013 What is Solar Radiation? Solar radiation is radiant energy emitted by the sun, particularly electromagnetic energy. About half of the radiation is in the visible short-wave part of the electromagnetic spectrum. The other half is mostly in the near- infrared part, with some in the ultraviolet part of the spectrum How does Carbon Dioxide influence a planets temperature? Earths Atmospheric Content What are the main Greenhouse Gases? How have CO2, CH4, and N2O levels changed in recent years? How exactly do greenhouse gases increase global temperature? Movement = Heat Solid LiquidGas Still confused??? Have you ever used one of these? -= How do we compare measure the impact of different greenhouse gases? r Since the industrial revolution when have the hottest recorded years been? Rank 1 = Warmest Period of Record: 18802013 YearAnomaly CAnomaly F (tie)* (tie)* (tie)* (tie)* (tie) (tie) How much higher are CO2 levels today compared to preindustrial levels? How about CH4? Petit et al 1999 The last 430,000 years: Greenhouse gas forcing Preindustrial Values:CO2 280 ppm CH4 660 ppb To-day: 397 ppm CO2 >30% 1830ppb CH4 >250% How do CO2 levels today compare with the past 800,000 years? EP Where do these regular changes in global temperature come from? So where do all these green house gases come from? The Bottom line Greenhouse gases in our atmosphere are necessary as they increase global temperatures to +15oC and thereby permit and abundance of liquid water on our planet From various proxy records, we know that levels of CO 2 fluctuate, and so does temperature The increase in CO 2 by humans has greatly accelerated what is otherwise a natural process Climate change is likely to continue accelerate in coming years Climate Change