Category Archives: climate models

Model structural uncertainty – are GCMs the best tools?

by Judith Curry

Rarely are the following questions asked:  Is the approach that we are taking to climate modeling adequate?  Could other model structural forms be more useful for advancing climate science and informing policy?

Continue reading

On the AR4’s projected 0.2C/decade temperature increase

by Judith Curry

“For the next two decades a warming of about 0.2C per decade is expected for a range of emission scenarios.” – IPCC AR4

Continue reading

The heart of the climate dynamics debate

by Judith Curry

Lennart Bengtsson’s recent statement on climate research has elicited a response from Andy Lacis, that directly points to the fundamental debate in climate dynamics.

Continue reading

How simple is simple?

by Tomas Milanovic

This essay has been motivated by Isaac Held’s paper [link] arguing for possible emerging simplicity or even linearity in climate dynamics.

Continue reading

UK-US Workshop Part IV: Limits of climate models for adaptation decision making

by Judith Curry

This post discusses Workshop presentations on the utility of climate models for regional adaptation decisions.

Continue reading

How far should we trust models?

by Judith Curry

In economics, climate science and public health, computer models help us decide how to act. But can we trust them? – Jon Turney

Continue reading

Workshop on the Roles of Climate Models

by Judith Curry

I am in the Netherlands, attending a Workshop on The Roles of Climate Models: Epistemic, Ethical, and  Socio-political Perspectives.

Continue reading

Implications for climate models of their disagreement with observations

by Judith Curry

How should we interpret the growing disagreement between observations and climate model projections in the first decades of the 21st century?  What does this disagreement imply for the epistemology of climate models?

Continue reading

Spinning the climate model – observation comparison: Part II

by Judith Curry

IPCC model global warming projections have done much better than you think. – Dana Nuccitelli

Continue reading

Nic Lewis on the UK Met Office on the pause

by Nic Lewis

These comments constitute a response to erroneous statements and misrepresentations made in a report published by the Met Office in July 2013: “The recent pause in global warming (3): What are the implications for projections of future warming?” (the Report).

Continue reading

Pause tied to equatorial Pacific surface cooling

by Judith Curry

Update:  New comment from Xie

My mind has been blown by a new paper just published in Nature.

Continue reading

Overestimated global warming over the past 20 years

by Judith Curry

Recent observed global warming is significantly less than that simulated by climate models. This difference might be explained by some combination of errors in external forcing, model response and internal climate variability.

Continue reading

Climate model simulations of the AMO

by Judith Curry

What are the implications of climate model deficiencies in simulating multi-decadal natural internal variability  for IPCC’s climate change detection and attribution arguments?

Continue reading

The forecast for 2018 is cloudy

by Judith Curry

The dramatic warming predicted after 2008 has yet to arrive.”

Continue reading

Climate vs weather prediction: should we rebalance?

by Judith Curry

The Weather Forecasting Improvement Act of 2013  introduced by Environment Subcommittee Vice Chairman Jim Bridenstine will prioritize the mission of NOAA to include the protection of lives and property, and make funds available to improve weather-related research, operations and computing resources.

Continue reading

Climate model tuning

by Judith Curry

Arguably the most poorly documented aspect of climate models is how they are calibrated, or ‘tuned’

Continue reading

How should we interpret an ensemble of models? Part II: Climate models

by Judith Curry

To solve these pressing problems, there needs to be much better recognition of the importance of probability models in climate science and a more integrated view of climate modelling whereby climate prediction involves the fusion of numerical climate models and statistical models. – Stephenson et al.

Continue reading

How should we interpret an ensemble of models? Part I: Weather models

by Judith Curry

Over the last two weeks, there have been some interesting exchanges in the blogosphere on the topic of interpreting an ensemble of models.

Continue reading

What are climate models missing?

by Judith Curry

Rather than reducing biases stemming from an inadequate representation of basic processes, additional complexity has multiplied the ways in which these biases introduce uncertainties in climate simulations. – Bjorn Stevens and Sandrine Bony

Continue reading

UK MSM on climate sensitivity

by Judith Curry

If climate scientists were credit-rating agencies, climate sensitivity would be on negative watch. But it would not yet be downgraded. – The Economist

Continue reading

Direct Statistical Simulation

by Judith Curry

[A] technique called direct statistical simulation dramatically reduces the time and brute-force computing that current simulation techniques require. The process does a good job of modeling fluid jets, fast-moving flows that form naturally in oceans and in the atmosphere. The findings are a key step toward bringing powerful statistical models rooted in basic physics to bear on climate science.

Continue reading

Spinning the climate model – observation comparison

by Judith Curry

In the past 6 months or so, we have seen numerous different plots of the CMIP5 climate model simulations versus observations.

Continue reading

Condensation-driven winds: An update

by Anastassia Makarieva, Victor Gorshkov, Douglas Sheil, Antonio Nobre, Larry Li

It’s official: our controversial paper has been published. After a burst of intense attention (some of you may remember discussions at Climate Etc., the Air Vent and the Blackboard), followed by nearly two years of waiting, our paper describing a new mechanism driving atmospheric motion has been published in Atmospheric Chemistry and Physics.

Continue reading

Clouds and MAGIC

by Judith Curry

Ocean clouds obscure warming’s fate, create ‘fundamental’ problems for models. – Paul Voosen
.

Climate model discussion thread

by Judith Curry

My perspective on climate models (uncertainty monster, DOE presentation, RS presentation) have been regarded as outside the ‘mainstream’.  Here are some new papers by leading climate modelers that provide new evidence and arguments on the concerns that I have been raising.

Continue reading