GEOG 303 Module 1 - Lecture 2 PDF
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Uploaded by IrreproachableCopernicium8566
ST 139
2024
David Barrett
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Summary
This lecture introduces the topic of climate change, focusing on the distinction between weather and climate. It outlines the climate change related term project and discusses fundamental questions surrounding climate change, including sustainability, rights of future generations and precautionary action. The lecture also covers climate variability, temperature anomalies and climate models.
Full Transcript
GEOG 303 Introduction - continued David Barrett ST 139 6 September 2024 Administration Everyone have access to D2L? Can everyone see assignment 1 and the associated dropbox? Please let me know if you have any issues going through the assignment 2 Administration...
GEOG 303 Introduction - continued David Barrett ST 139 6 September 2024 Administration Everyone have access to D2L? Can everyone see assignment 1 and the associated dropbox? Please let me know if you have any issues going through the assignment 2 Administration Term project A series of climate change-related reflections based on news media reporting from a reputable source Entry 1: September 9 – 23 Entry 2: September 24 – October 7 Entry 3: October 8 – 21 Entry 4: October 22 – November 4 Entry 5: November 5 – 18 Entry 6: November 19 – December 2 3 Administration You will reflect on a selected news article with a series of prompts (details in the assignment outline, uploaded to D2L) What aspect of climate change is being reported on? What prompted the article? What is being said about the article on social media? How do the findings or events reported on impact you? If you were talking to roommates or family about this article, how would they respond? Is the report being “both-sided”? What is the credibility of the reporting? 4 Administration Total length of each entry should be MAX 1000 words. Due on the last day of classes 5 How do you see / hear climate change discussed? 6 7 8 9 The Euphrates River, Turkey and Iraq, August 2022 The top 10 weather stories of 2023 (in Canada) 1. Record wildfires 2. Canada cloaked in smoke 3. Hottest Summer – on Earth and in Canada 4. Deadly deluge in Nova Scotia 5. Canada dry in the West and wet in the East 6. Hurricane Lee… no Fiona but more than a windy day 7. April glaze storm in Montréal-Ottawa – more beast than beauty 8. Cold spells in a warm year 9. Flooded out: Québec’s Record Wet July 10. Canada Day tornado in Alberta 16 Weather vs climate “Climate is what you expect. Weather is what you get” – Mark Twain (or others, unclear) 17 Weather vs climate Climate: The long-term average weather at a specific location or region. Including mean values and ranges of what is ‘normal’. Weather: The specific state of the atmosphere at any point in space and time Precipitation Temperature Snow Winds Etc Generally, we use a period of 30-years to calculate the climate ‘normal’. More or less equivalent to one generation – relates to what we experience and 18 remember 1990-2020 climate normals - CALGARY 19 Climate variability One particularly challenging component of the discussion around climate change is variability. Given that we average values out over 30 years to get normals, it takes a while to observe these changes. Repeated anomalies result in a slow adjustment of the normal Very difficult to tie specific weather events to climate change Patterns emerge over time 20 Climate variability Climate variability: Is the interannual and decadal fluctuations around climate normals (the ‘mean state’ or averages) Climate change: In contrast a change to the mean state. For example, mean temperatures for 1981 – 2010 were higher than those of 1971 – 2001 in most of Canada. One way we often look at this is with climate modeling and historical reconstructions 21 22 23 Climate variability Statistics are important 24 Anomalies In climate change studies, temperature anomalies are more important than absolute temperature. A temperature anomaly is the difference from an average, or baseline, temperature. The baseline temperature is typically computed by averaging 30 or more years of temperature data. A positive anomaly indicates the observed temperature was warmer than the baseline, while a negative anomaly indicates the observed temperature was cooler than the baseline. This standardization is important so that short term ‘weather’ fluctuations are minimized 25 Anomalies example 26 Spatial variability 27 28 1885-2021: 3.8C Calgary mean annual 1970-2000: 4.0C temperature, 1885-2021 1990-2020: 4.4C Trend: +0.9C/century Since 2010: 4.6C Mean annual temperature, YYC T (C) 7.0 2021: 5.4C 6.0 5.0 4.0 3.0 2.0 1.0 0.0 1885 1905 1925 1945 1965 1985 2005 2021 Year 1885-2021: Calgary mean winter 8.1C 1970-2000: 7.5C temperature, 1885-2021 1990-2020: 6.6C Trend: +2.1C/century Since 2010: 6.7C T (C) Average Winter (DJF) Temperature, Calgary 2021: 6.0C 0.0 -2.0 -4.0 -6.0 -8.0 -10.0 -12.0 -14.0 -16.0 -18.0 1885 1905 1925 1945 1965 1985 2005 2021 Year 1885-2021: Calgary minimum 34.6C 1970-2000: 34.0C temperature, 1885-2021 1990-2020: 31.8C Trend: +4.9C/century Since 2010: 30.7C Minimum Annual Temperature, T (C) Calgary 2021: 32.9C -13.0 -18.0 -23.0 -28.0 -33.0 -38.0 -43.0 1885 1905 1925 1945 1965 1985 2005 2021 Year North American trends Fundamental questions Important that we acknowledge fundamental questions in the climate change discussion (from textbook page 5): Is the current mode of development in the West (and elsewhere) sustainable? What right does any one group have to affect the well-being of current and future generations? Who should pay to solve a problem – those who created in the first place or those who are most likely to contribute to it in the future? How certain must we be about the science before we take precautionary action? 33 State of the science One reason this course spans the natural/physical sciences and social is because there is already a consensus among scientists that climate change is happening and is being driven by humans “… the scientific questions… are not about whether the climate is changing, or even whether human actions influence climate, but how fast and how much climate will change.” pg 9 of textbook From the IPCC AR6 report: 34 Next class We will wrap up our introduction module by discussing some overarching climate change policies, some framing around the climate change debate, atmospheric science Please read pages 10-12 of your textbook Let me know if there are any issues with the assignment Please also look through pages 4-7 of the AR6 summary document – we’ll discuss a few of them on Monday. https://www.ipcc.ch/report/ar6/syr/downloads/report/IPCC_AR6_SYR_SPM. pdf Have a great weekend! 35
