geography discussion 6

IPCC

In previous weeks’ lectures, we looked over some important figures used in the IPCC

(Intergovernmental Panel on Climate Change) assessment report. At this time, it is

important for us to learn about the IPCC; who are they and what do they do. Being on

the front line to educate policy makers in the world, the IPCC has been attacked by many

climate skeptics/deniers on their false and mistaken belief that the IPCC is an

organization established on bias and skewed scientific results. Please read carefully what

is posted in this lecture slide about the “IPCC”. As you can see, the IPCC’s perspective is

to minimize any bias associated with political/national/academic/economic affiliations.

The IPCC does not create/interpret their own data. They merely report/summarize the

results that are published in peer-reviewed academic journals.

One example of an organization who attacks the IPCC is the NIPCC (Nongovernmental International Panel on Climate Change): http://climatechangereconsidered.org (Please also read “NIPCC – About the IPCC”

http://climatechangereconsidered.org/about-the-ipcc/)

The NIPCC is a website that has a clean, professional look, a nice aesthetic effect, and

does not pop up any advertisements each time you open it. When you see a web site like

this you are included to believe the content because it suggest that the website is well

funded. This is an extreme case of an organization that looks believable because their

web site is very well-funded, which creates great camouflage to obscure their actual

agenda. It takes some digging into to discovery who is responsible for the posted articles

and who is funding their web site.

For example, please go to the page “About” and open “About the NIPCC”. http://climatechangereconsidered.org/about-the-nipcc/

In the third paragraph, please find a sentence starting “NIPCC traces its beginnings to an informal meeting held in Milan, Italy in 2003 organized by Dr. S. Fred Singer and the Science & Environmental Policy Project (SEPP).” You may remember Dr. S. Fred Singer from the documentaries we reviewed in bi-weekly discussion (e.g. Merchant of Doubt). Dr. Singer is a climate skeptic who was also involved in the Tobacco debate back in the day. Within the information written in plain and professional terms in this website, the connection between Dr. Singer and SEPP is actually quite vague and does not provide much information to us. Hense, we need to do little further digging. Please go to: https://en.wikipedia.org/wiki/Fred_Singer

And please read “SEPP and funding” on this Wikipedia page (Wikipedia is a web resource that you cannot cite in your academic paper since anyone can edit and modify the information. Therefore, it is a non-credible resource unless it is based on trustworthy resources).

Now, who has the conflict of interest – IPCC or NIPCC?

IPCC Assessment Reports Cambridge University Press, Cambridge, Great Britain, New

York, NY, USA and Melbourne, Australia

1990 1995 2001

2007 2014 2022

The IPCC published its assessment report every 6-7 years since 1990. The latest report is called the 6th assessment report and was released through 2021 to 2022. Currently, the final piece of the 6th assessment report, which is the synthesis report, is under way and is expected to be published in September of 2022.

In the process of publishing their 6th assessment report, the IPCC released

special reports.

Special Report on Global Warming of 1.5 ºC (9/25/2019)

https://www.ipcc.ch/sr15/

Special Report on the Ocean Cryosphere and and changing Climate (10/8/2019)

https://www.ipcc.ch/srocc/home/

Special Report on Climate Change and Land

https://www.ipcc.ch/srccl/

The best way to understand important messages in the IPCC report is by

reviewing the "Summary for Policymakers", which is a shorter version of the

original report prepared for policymakers who are generally busy and lack time

to read the entire report. Figures are of particular importance, some of which

are introduced and included in the previous lecture slides. Here, I am sharing

two separate links for the "Summary for Policymakers":

https://www.ipcc.ch/site/assets/uploads/sites/2/2019/05/SR15_SPM_version_r

eport_LR.pdf

https://www.ipcc.ch/site/assets/uploads/2018/02/AR5_SYR_FINAL_SPM.pdf

https://www.ipcc.ch/srccl/chapter/summary-for-policymakers/

In 2007, IPCC and Albert A. Gore Jr. jointly received the Nobel Peace Prize!

Page | 15

Emissions and concentrations, forcings and temperature anomalies

Each Representative Concentration Pathway (RCP) defines a specific emissions trajectory and subsequent radiative forcing (a radiative forcing is a measure of the influence a factor has in altering the balance of incoming and outgoing energy in the Earth-atmosphere system, measured in watts per square metre):

Name Radiative forcing CO 2

equiv (p.p.m.)

Temp anomaly

(°C)

Pathway SRES temp

anomaly equiv

RCP8.5 8.5 Wm2 in 2100 1370 4.9 Rising SRES A1F1 RCP6.0 6 Wm2 post 2100 850 3.0 Stabilization without overshoot SRES B2 RCP4.5 4.5 Wm2 post 2100 650 2.4 Stabilization without overshoot SRES B1 RCP2.6 (RCP3PD)

3Wm2 before 2100, declining to 2.6 Wm2 by 2100

490 1.5 Peak and decline None

Table 4: from Moss et.al. 2010. Median temperature anomaly over pre-industrial levels and SRES comparisons based on nearest temperature anomaly, from Rogelj et.al. 2012

Radiative Forcings

The graph below shows radiative forcing trajectories for the four RCPs, the other candidate scenarios that informed the final versions, and the modelling group associated with each.

Figure 7: Changes in radiative forcing relative to pre-industrial conditions. Bold coloured lines show the four RCPs; thin lines

show individual scenarios from

approximately 30 candidate RCP

scenarios that provide

information on all key factors

affecting radiative forcing…

(Moss et.al., 2010)

The forcing trajectories are consistent with socio-economic projections unique to each RCP. For example, RCP2.6 (RCP3PD) assumes that through drastic policy intervention, greenhouse gas emissions are reduced almost immediately, leading to a slight reduction on today’s levels by 2100. The worst case scenario - RCP8.5 - assumes more or less unabated emissions.

Climate Projections

This table shows the condition of future projections, originally published in 2010, modified and included in the IPCC assessment report.

What does this mean?

The left hand side column is the name of the future scenario (RCP8.5, RCP6.0,…). The name of each scenario is based upon the amount of projected radiative forcing created by CO2 emitted into the atmosphere by year 2100. In this table, the simulation of RCP 2.6 assumes rapid reductions in emissions – more than 70% cuts from current levels by 2050 – and a corresponding, much smaller, amount of warming and far less precipitation change. On the other hand, other scenarios (RCP 8.5, 6.0. and 4.5) assume continued increases in emissions, with associated large increases in warming and major precipitation changes. With the current way of life, our future may fall into any of those scenarios. With this, all scenarios except for RCP 2.6 are called “business as usual” models. RCP 8.5 is specifically known for the most fringe (extreme) scenario.

Based on the condition provided in the previous slide, this is the future temperature change projection up to year 2100. The black line is the historical temperature variation since 1950 with gray shaded area being an associated margins of error. The red line within the shaded areas is the future temperature change following the most extreme case, RCP8.6 (this is the worst case scenario!), while the blue line with shaded area is RCP2.6, the only scenario with mitigation. In the worst case scenario, RCP8.5, the temperature may become as high as close to 5.5 C higher than global average temperatures in 2005. The numbers shown in the figure indicate the number of simulations run to obtain results.

Greenland Ice Sheet simulations by year 3000 using PCR 2.6, 4.5, and 8.5 models.

Observed state is as of 2008.

This ice sheet may disappear in 979 years from now!

Science, Aschwanden et al. 2019 https://www.science.org/doi/10. 1126/sciadv.aav9396

PCR simulations applied to Greenland Ice Sheet

IPCC 2019: Technical Summary

Along with previously shown temperature change (a), the figure (b) shows the

changes in sea level rise. Even RCP2.6, a scenario with mitigation, the sea level

continues to increase for the next 100 years. This is because sea level rise is

caused by warming of the ocean (thermal expansion), loss of ice by glaciers and

ice sheets, and reduction of liquid water storage on land. And, according to the

IPCC assessment report, even with scenario RCP2.6, it is projected that the global

glacier volume will decrease by 15 to 55%!

The IPCC report (Technical Support, 2019) confirms accelerating sea level rise,

noting with high confidence that “Areas of concern in earlier IPCC reports, such

as the expected acceleration of sea-level rise, are now observed.” That

acceleration is largely the result of faster melting of the Greenland and Antarctic

ice sheets. Over the past decade, the amount of ice loss from the Greenland ice

sheet has doubled as compared with the rate during the previous decade, and

ice loss from Antarctica has tripled. The IPCC report concluded that if the world

meets the Paris Climate Agreement target of no more than a 2 degrees C (3.6

degrees F) warming, sea-level rise could increase by 1-2 feet by 2100 and by a

total of 3 feet by 2300; in a worst case high-emissions scenario (RCP8.5), sea

level would increase by 3 feet by 2100 and by 12 feet by 2300.

Ocean heat content increase globally (top frame) and in four ocean basins (bottom frames). Illustration: Wang et al. (2017), Climate Dynamics

https://www.theguardian.com/enviro nment/climate-consensus-97-per- cent/2017/jun/26/new-study- confirms-the-oceans-are-warming- rapidly

Figure from Wang et al., showing the evolution of El Niño events from 1901 to 2017. (Bin Wang)

https://www.washingtonpost.com/weather/2019/10/22/super-el-nio-events-may-become-more-frequent- climate-warms/?amp=1

Strong El Niño events may become more frequent as the climate warms

https://www.nature.com/magazine-assets/d41586-019- 02897-7/d41586-019-02897-7.pdf

IPCC report has been describing that, since world’s oceans are losing power to stall climate change, “more powerful storms, increased risk of flooding and dwindling fisheries if greenhouse-gas output doesn’t fall”.

Change in average surface TEMP and PRECEP change (20-year mean) vs observed 1985-2020 IPCC 2022

Observed 1985

Here we see figures from the IPCC AR6 showing the difference between simulated climate model results based on temperature increases, which are 1.5C (left), 2C (middle), and 4C (right), and observational data from 1985 to 2020. These scenarios show in different degrees both warming trends toward the Polar regions and decreases in precipitation in the lower-mid latitudes, showing increases in potential future drought areas.

Figure. Future increases in lightning flash rate may initiate a feedback that amplifies the impacts of climate change in high- northern-latitude terrestrial ecosystems.

Chen et al. (2021) Nature Climate Change https://www.nature.com/artic les/s41558-021-01011-y

As the Arctic warms and polar amplification increases, Chen et al. published a study in April 2021 suggesting that, based on satellite observations and statistical analysis, there is a strong positive correlation between a warming Arctic region and increasing numbers of lightning flashes. Increasing lightning in turn will lead to a greater number of wildfires that will increase GHG emissions.

Effects on Agriculture and the Ocean?

These figures from the IPCC report showing discrepancy between simulated climate model results 2080-2099 and observational data 1980-1999. Precipitation, soil moisture, runoff, and evaporation, which are the factors that will directly affect agricultural potential in the future. As you see, the impact of climate change is not universal. Some region experiences enhanced precipitation while other regions experience drier condition.

Let’s learn about this pattern in the following slide.

https://www.nytimes.com/interactive/2019/08/06/climate/world-water-stress.html World Water Stress Projection

https://www.wri.org/blog/2019/08/17-countries-home-one-quarter-world-population-face-extremely-high-water-stress

The Aqueduct Water Stress Projections Data include indicators of change in water supply, water demand, water stress, and seasonal variability, projected for the coming decades under scenarios of climate and economic growth.

World Resources Institute; United Nations

Groundwater is water held underground in the soil or in pores and crevices in rock. Groundwater is particularly important to water-stressed regions. When a city or a country uses nearly all available water, a bad drought can be catastrophic. Please note that a large area in central to south US is under significant water stress. We will observe this further in the following slides.

https://static01.nyt.com/newsgraph ics/2019/08/01/world-water- stress/2fe9b6708dcfb299b9949e1b c35e859322184879/projection.gif

Solomon et al. (2009) IPCC AR5

This is an important IPCC figure showing “expected global distribution of precipitation” change along with increasing temperature (per kelvin). In general, we know that when atmospheric temperatures rise, evaporation is enhanced and more moisture exists in the atmosphere. The moisture will be condensed when the air is adiabatically cooled and saturated. Hence, more warming, more precipitation. Right? However, this figure shows that the precipitation pattern will not be homogeneous. Please take a moment to observe this figure and take note about what type of pattern you see.

You may see increasing precipitation (shown in blue) in the polar region. Also, you may see an increasing precipitation pattern near the equator. Great! That must be the area of ITCZ (Intertropical Convergence Zone) - a place where you can observe consistent heavy rain as we learned earlier in the semester. Do you also see bands of less precipitation that occur north and south of the ITCZ, perhaps around 30 degrees north and south (shown in yellow to red)? Related to the ITCZ, you may remember the Hadley Cell Circulation. At 30 degrees north and south are areas where the air circulation is approximately vertical, initiated at the ITCZ (i.e. no/little precipitation in general - air is dry). Therefore, most of the greatest deserts exist at this latitude.

This figure is showing that currently dry regions will become drier when temperatures increase!

What happens in the US? It is suggested that there will be a significant decrease in precipitation mainly in the south west – near the Mojave Desert!

This figure shows a strong drought pattern observed in 2016. This was toward

the end of the great drought that continued over decades in the western US.

2016 was a somewhat unusual year for us in MA because, as some of you might

remember, we also experienced below average precipitation for consecutive 7

months of that year and many cities in MA issued water restrictions. Concerning

major drought patterns, the latest IPCC report suggests that this will become

more consistent and prominent as temperatures rise.

Latest United States Drought Monitor: https://droughtmonitor.unl.edu

Here is a maps of observed precipitation change from 1901 to 2020 and from

1951 to 2010 reported in IPCC AS5.

IPCC AS5: https://ar5-syr.ipcc.ch/resources/htmlpdf/WG1AR5_SPM_FINAL/#pf6

EOS Earth & Space Science News

(2017)

More publications report in support of previous study.

(Alizadeh et al. 2020 Science Advances)

In 2020, a paper published in Science Advances proves our perception about droughts and heat waves – the study shows that combined droughts and heat waves have been occurring more and more frequently in recent decades!

MacDonald (2010)

TEMP

PRECIP

Drought Severity Index (2001-2009)

A figure published in Proceedings of the National Academy of Sciences in 2010. It shows recent changes in temperature, precipitation, and drought index in the US. As you can see, it is more enhanced warming and drying in the west.

Colorado River: Running Near Empty Please watch this amazing documentary published by Yale University to further understand the impact of drought. Enjoy!

http://e360.yale.edu/feature/video_colorado_river_running_near_e mpty/2443/