Source document: https://docs-lawep.s3.us-east-2.amazonaws.com/1697630097602.pdf (Australia)
Question on notice no.

7 Portfolio question number: SQ21-000645 2021-22 Budget estimates Environment and Communications Committee, Agriculture, Water and Environment Portfolio Senator Malcolm Roberts: asked the Bureau of Meteorology on 24 May 2021— Looking at 100 years of data BOM has only projected a linear trend for the future temperatures.

What are the 95% confidence intervals on the predictions based on this trend?

BOM claims a current and ongoing warming trend, somewhat linear.
Is BOM advising the public and parliamentarians that a linear trend of Australian air temperatures and secondly of global atmospheric temperatures is a realistic and accurate forecast of the future?

Is BOM advising that a linear trend extrapolating along a linear trend is the way to predict future temperatures?

Where are the error bounds on the forecast based on the linear trend you're calculated and projected?
Is BOM advising the public and parliamentarians that this linear trend line represents a statistically significant and narrow band for future temperatures in Australia, and secondly, globally?

Are you asserting that the residuals resulting from BOM's linear trend are random and so support the linear trend as a valid statistical model of the period?
Note: Residuals mean the difference between the latest empirical measurements/observation and the model's equivalent projection for the same date based upon previous measurements/ observations.

6.1 What is BOM projecting for temperature for the years 2100 and 2120 for various levels of human CO2 production including: a.

Business as usual b. Paris ''Agreement compliance'' globally?

Please specify the statistical methods and parameters/assumptions used to make the temperature projection.
6.2 What is BOM projecting as the rate of temperature rise from now through to 2100 and 2120 for various levels of human CO2 production including: a.

Business as usual b. Paris ''Agreement compliance'' globally?

Please specify the statistical methods and parameters/assumptions used to make the temperature projection.

Answer — Answer attached.


Environment and Communications Answers to questions on notice Agriculture, Water and the Environment Portfolio Question No: SQ21-000642 Hearing: Outcome: Budget Estimates Agency Division/Agency: Bureau of Meteorology Topic: Past and present temperatures and rate of temperature change Question Date: 15 June 2021 Question Type: Written Senator Roberts asked: 5.1.
According to BOM what is the rate of warming in Australian atmospheric temperatures using BOM temperature data for the following periods: i.

1910 to present?

ii.

Last 42 years starting with 1979?

iii.

Last 26 years starting with 1995?

Please specify the rate of temperature change in degrees per decade.

Please specify the statistical methods and parameters/assumptions used to determine the rate of temperature change.

5.2.
5.2.

According to BOM what is the rate of warming in Australian atmospheric temperatures using University of Alabama Huntsville (UAH) data from NASA satellites for the following periods: i.

Last 42 years starting with 1979 ii.

Last 26 years starting with 1995 Please specify the rate of temperature change in degrees per decade.

Please specify the statistical methods and parameters/assumptions used to determine the rate of temperature change.

5.3.
5.3.

According to BOM what is the rate of warming in global atmospheric temperatures using BOM/GHCN/NOAA data for the following periods: i.

1910 to present ii.

Last 42 years starting with 1979 iii.

Last 26 years starting with 1995 Please specify the rate of temperature change in degrees per decade.

Please specify the statistical methods and parameters/assumptions used to determine the rate of temperature change.

5.4.
5.4.

According to BOM what is the rate of warming in global atmospheric temperatures using UAH satellite data for the following periods: i.

Last 42 years starting with 1979 ii.

Last 26 years starting with 1995 Please specify the rate of temperature change in degrees per decade.

Please specify the statistical methods and parameters/assumptions used to determine the rate of temperature change.
Answer: 5.1 The Australian Climate Observations Reference Network – Surface Air Temperature (ACORN-SAT) version 2.1 dataset shows that Australia's temperature has increased by: i.

0.13 ± 0.02 °C per decade since 1910 ii.

0.22 ± 0.09 °C per decade since 1979 iii.

0.34 ± 0.19 °C per decade since 1995 In relation to the statistical method, a trend line has been calculated using the technique of ordinary least squares regression.

5.2 This request does not relate to Bureau activity.
The Bureau is not responsible for this data set, and the University of Alabama should be requested to analyse their data to answer this question.

5.3 This request does not relate to Bureau activity.

The Bureau is not responsible for this data set, and the GHCN and NOAA should be requested to analyse their data to answer this question 5.4 This request does not relate to Bureau activity.
The Bureau is not responsible for this data set, and the University of Alabama should be requested to analyse their data to answer this question.

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