rebuttal cards Flashcards
“Global Warming Myth and human impact”
• “It is unequivocal that anthropogenic increases in the well-mixed greenhouse gases (WMGHGs) have substantially enhanced the greenhouse effect, and the resulting forcing continues to increase.” (Myhre, 2013, p.661)
“Temperatures have been lower in last 12 months compared to other years”
- Temperatures may have been lower in certain areas however; the average global land and Ocean Temperature for January-October 2017 was 0.86oC above the 20th century average of 14.1oC which is the third highest average on record from 1880-2017 (NOAA National Centers for Environment information, 2017)
- This data could have been an anomalous, global warming can’t be dismissed with only one year of data.
“Global mean temperatures have declined in the last decade during the climate change hiatus”
- The general increasing pattern can be effected by climate variability, this can sometimes enhance or counteract the long term externally forced trend (Flato et al., 2017, p.769).
- The term hiatus is misleading and suggests global warming has stopped however it is better described as a slowdown or pause in the increase of global surface temperature. (Yan et al., 2017)
“Temperatures taken from urban areas and the Urban Heat Island (UHI) effect”
• UHI is a local phenomenon but it is “unlikely that any uncorrected UHI effects have raised the estimated centennial globally averaged LSAT trends by more than 10% of the reported trend” (Hartmann, 2013, pp.187-188)
“Human CO2 emissions warming the climate is a fallacy”
• Anthropogenic emissions of CO2 have led to radiative forcing (RF) of 1.82Wm-2 meaning the total radiative forcing is positive. CO2 concentration has been the largest contributor to radiative forcing in the atmosphere since 1750. If the total radiative forcing has led to an uptake of energy in the atmosphere. These radiative forcing’s result in an eventual temperature response (IPCC, 2013, pp.9-12)
“Water vapour has the largest greenhouse effect not CO2”
• It is true that water vapour is the largest contributor to the natural greenhouse effect however the properties of water are different to other greenhouse gases. Water can condense and precipitate and 10 days is it’s a typical residence time in the atmosphere. It does not contribute significantly to the long-term greenhouse effect and its concentration is dependant of temperature. This leads to it being thought as a feedback agent rather than climate forcing agent. The anthropogenic emissions of water vapour are so small it does not have an impact on overall climate change. (Myhre et al., 2013, pp.666-667)
“Man-made CO2 emissions represent a fraction of global CO2 emissions”
• The carbon cycle is naturally in equilibrium with fluxes between the ocean the atmosphere and biosphere. The anthropogenic impact distorts this balance due to the creation of a new flux from rocks to the atmosphere through the burning of fossil fuels. This knocks the cycle out of equilibrium due to combustion of carbon at a faster rate than it is created in rocks. (Dessler, 2016)
“CO2 lags behind temperature therefore temperature causes rising CO2”
• In the past, conditions affecting these two factors were natural causing the change in temperature before the CO2 would react accordingly. This is not the current state of the atmosphere due to RF, this leads to temperature now lagging behind CO2 increase. (Vakulenko et al., 2015)
“Temperatures in Europe being this high before”
• There is high confidence warming in the medieval warm period only occurred in certain areas of the world, warming since the mid 20th century is more synchronous. It is believed with high confidence this event was caused by solar forcing’s and internal variability. (Masson-Delmotte, 2013, p.386)
“Weather VS Climate models”
- Although climate and weather models are similar the spatial resolutions and parameters of models can be very different (NOAA National Centers for Environment information, 2017)
- Weather models are used to predict specific events in the near future whereas climate models are used to predict general trends in the atmosphere further into the future. (NOAA National Centers for Environment information, 2017)
“Climate models are unreliable and do not represent the complexity of the issue”
- Climate model’s simulations and observations between 1951 and 2012 agree to a high level of confidence (Flato et al., 2017, p.769).
- Our understanding of natural modes and adapting out models to incorporate advances in the science is what further develops their reliability.
