June 18, 2019,      Sea Day,   Fantastic Lecture on Climate Change.   158/183

My presentation is a reproduction of Dr. Peter Bobrowsky's lecture on climate change.  He gave a fantastic chronology on historical climate change over thousands of years as well as explaining in great detail how scientists around the world are able to measure and predict climate change.  His presentation should be mandatory viewing for everyone and I hope my comments below adequately reproduce his story.

One way I can encapsulate Peter's presentation -  Understanding chronological climatic history by deposition to predict the future.  Nature's filing cabinet!

In summary, there will be another glaciation period on Earth in a few thousand years!  Question is - How much will temperatures increase in this cycle during the interglacial period!  This presentation will help us to understand the supporting evidence.

I was pleased to learn that Peter lives in Sydney, BC.  Merrilynne and I visit there once a week for our coffee break during cycling.  We will be getting to know Peter better and I am sure Emma will be interested in Bob's knowledge in one of his many professional areas of expertise, specifically Geology.


Photos are taken from Peter's powerpoint presentation.

Another relevant quote

Thermometers were invented 400 years ago, so temperature records for earlier periods are imputed in numerous ways.  Proxy Records

Understanding climatic history through science.


Global temperatures have been gradually increasing for seventy of the past 100 years.


1000 year history shows a significant warming in the last 100 years.

Tree ring width reflects weather and moisture availability

Corals  contain excellent information on sea water composition over centuries

Material deposited in successive layers over thousands or millions of years is a great source of historical climate information.

Coring deposits for chronological evaluation of sediment.

Core locations, provide ice cores millions of years old.

Chronological history by deposition.  Nature's filing cabinet!

Microscopic sections cut from the ice cores, containing atmospheric samples for analysis, plus deposited particles spanning millions of years of ice accumulation.  Carbon levels can be measured directly from entrained air for millions of years from one core. 

Pollens cover all plant species, giving huge amounts of historical information, chemical composition, types of plants in areas over thousands of years,  etc.

Ice age coverage.  Arizona looks attractive!

Land bridging between Asia and North America

Great Britain connected to Europe

Sea level changes over 2 million year period

Earth was much warmer 8000 years ago.  This is about the time that 1000 pound sloths lived in the Arizona area.  A skeleton can be seen the in Karchner Caves near Tucson.

Obviously we are coming out of an Ice age and Earth's average temperatures have not reached temperatures of other interglacial periods.

In addition to these points, methane is reputed to cause 1/4 of the man made global warming.  Methane is up to 84 times as problematic carbon dioxide, but it has a short 100 year atmospheric life.

Sulfur dioxide does not not cause warming but it combines with water to form sulfuric acid.

Heat gain from the sun is impacted by solar radiation, which in turn is a function of sun spots, solar convection currents, etc.

Precession is the change in the angle of earth's tilt on a cyclical basis.  Think of the axis of a spinning top wobbling.

Angle between the elliptic and celestial plane.

Orbital eccentricity varies distance from the sun.

Obvious correlation of these factors to glaciation and heating........ :)

Multiple estimates, all indicating sea level increases

Now this is factual.  Causes are multiple, such as erosion, land settlement and sea level increase

There WILL be another ice age but the question is how hot will the inter glaciation period be?

Sadly, this fake cover was held up as evidence of conflicting scientific evidence by the present "Administration" in their continuing diatribe on the subject! Just one example of distorted information meant to manipulate uninformed people.  How will the average person ever learn the truth?