Tag Archives: climate change

doubling of El Nino

1 Reply

Nature Climate Change says El Nino frequency could double due to climate change. The result: “severely disrupted global weather patterns, affecting ecosystems4, 5, agriculture6, tropical cyclones, drought, bushfires, floods and other extreme weather events worldwide3, 7, 8, 9”

El Niño events are a prominent feature of climate variability with global climatic impacts. The 1997/98 episode, often referred to as ‘the climate event of the twentieth century’1, 2, and the 1982/83 extreme El Niño3, featured a pronounced eastward extension of the west Pacific warm pool and development of atmospheric convection, and hence a huge rainfall increase, in the usually cold and dry equatorial eastern Pacific. Such a massive reorganization of atmospheric convection, which we define as an extreme El Niño, severely disrupted global weather patterns, affecting ecosystems4, 5, agriculture6, tropical cyclones, drought, bushfires, floods and other extreme weather events worldwide3, 7, 8, 9. Potential future changes in such extreme El Niño occurrences could have profound socio-economic consequences. Here we present climate modelling evidence for a doubling in the occurrences in the future in response to greenhouse warming. We estimate the change by aggregating results from climate models in the Coupled Model Intercomparison Project phases 3 (CMIP3; ref. 10) and 5 (CMIP5; ref. 11) multi-model databases, and a perturbed physics ensemble12. The increased frequency arises from a projected surface warming over the eastern equatorial Pacific that occurs faster than in the surrounding ocean waters13, 14, facilitating more occurrences of atmospheric convection in the eastern equatorial region.

climate change impacts

Leave a reply

Here are a couple projections of climate change impacts.

The World Health Organization projects “Between 2030 and 2050, climate change is expected to cause approximately 250 000 additional deaths per year, from malnutrition, malaria, diarrhoea and heat stress.” This sounds awful, and of course it is. But if you compare this to other preventable causes of death like traffic accidents, smoking and air pollution, you could probably save a lot more lives with a given amount of money focusing on the latter group than exclusively on climate change.

A more sobering projection, at least to me, comes from an organization called DARA.  Although the report includes some truly awful and incomprehensible infographics, there is a very clear graphic on p. 21. Under a “no action” scenario, climate change subtracts about 3% from world economic growth in 2050 and 7-8% in 2100. If you believe technology will lead to a massive acceleration of economic growth, we may be able to afford even this (although our children will be learning about Earth’s original native ecosystems in history class). If long-term growth stays in the sub-5% range where it has been recently, this will mean the decline and fall of civilization as we know it.

Washington State drought

Leave a reply

Washington State has a snowpack problem.

“Snowpack is down to just 16% of normal,” Inslee said. “This is an unprecedented low. Several mountain areas have already melted out and have little to no measurable snow left…. On the Olympic Peninsula, where there would normally be 80 inches of snow today in the mountains, the glacier lilies are blooming.”

No mandatory rationing has been ordered, but because conditions recently worsened, Inslee took the step to declare the statewide emergency. Fellow Democratic Gov. Jerry Brown of California declared a statewide drought emergency in 2014, and last month ordered municipalities across the state to cut water use by 25%.

In Oregon, Gov. Kate Brown has declared a drought emergency in seven of the largest counties. Seven other counties have requested that an emergency be declared. Combined, that’s about two-thirds of the state.

El Nino

Leave a reply

More El Nino coverage from Slate. It’s going to be the strongest since 1998! or 2010! or ever!

First off, it’s rapidly intensifying. El Niño is about self-reinforcing feedbacks between the ocean and the atmosphere, and from all accounts, this one has its foot on the accelerator pedal.

If it continues, the impacts will be felt around the globe—here’s my detailed rundown of what to expect. Among them: drought in Australia, Southeast Asia, and perhaps India, with flooding in Peru and Southern California.

climate change impact reports

Leave a reply

Here are a number of reports on climate change impacts on U.S. cities:

The common thread is that extreme weather is going to be more frequent and more damaging, and we need to be ready.

400 ppm

Leave a reply

Yes, we’re at 400 ppm of carbon dioxide in the atmosphere, consistently now, everywhere. As a reminder, the pre-industrial number was something like 280.

For the first time since we began tracking carbon dioxide in the global atmosphere, the monthly global average concentration of this greenhouse gas surpassed 400 parts per million in March 2015,  according to NOAA’s latest results.

“It was only a matter of time that we would average 400 parts per million globally,” said Pieter Tans, lead scientist of NOAA’s Global Greenhouse Gas Reference Network. “We first reported 400 ppm when all of our Arctic sites reached that value in the spring of 2012. In 2013 the record at NOAA’s Mauna Loa Observatory first crossed the 400 ppm threshold. Reaching 400 parts per million as a global average is a significant milestone.

From a non-scientific sample of people I know, people who thought they were immune from seasonal allergies seem to be suffering them for the first time, and people who have always suffered them, which includes me, are reduced to slobbering insomniac messes. Could there possibly be a connection?

recycled water

Leave a reply

Recycled water, i.e. treating sewage back to drinking water standards, has been around for awhile and doesn’t raise many eyebrows in truly water scarce areas. Which is why it is getting more popular and less controversial in California cities. Here are some fun pictures of politicians drinking it out of beakers with big smiles on their faces.

Which, maybe because we are in mayoral election season here in Philadelphia, reminded me of this great scene from The Wire.

 

April 2015 in Review

1 Reply

Negative stories:

Positive stories:

  • Mr. Money Mustache brought us a nice post on home energy efficiency projects. This was a very popular post.
  • Biotechnology may soon bring us the tools to seriously monkey with photosynthesis. (This is one of those stories where I struggle between the positive and negative columns, but clearly there is a potential upside when we will have so many mouths to feed.)
  • Donald Shoup, author of The High Cost of Free Parking, is retiring. That might sound bad, but his ground-breaking ideas are continuing on and actually seem to be going mainstream.
  • Lee Kuan Yew, who took Singapore “from third world to first” in one generation, passed away (in March, but I wrote about it in April. Let me be clear – I am an admirer and it is his life I am putting in the positive column, not his death.)
  • Donella Meadows explained how your bathtub is a dynamic system.
  • Robert Gordon offers a clear policy prescription for the U.S. to support continued economic growth.
  • I explain how a cap-and-trade program for stormwater and pollution producing pavement could work.
  • Joel Mokyr talks about advances in information technology, materials science and biotechnology.
  • Some U.S. cities are fairly serious about planting trees.
  • Edmonton has set a target of zero solid waste.
  • Saving water also saves energy. It’s highly logical, but if you are the skeptical type then here are some numbers. Also, urban agriculture reduces carbon emissions.
  • Peter Thiel thinks we can live forever. (positive, but do see my earlier comment about mouths to feed…)
  • A paper in Ecological Economics tries to unify the ecological footprint and planetary boundary concepts.
  • Philadelphia finally has bike share.

downscaling

Leave a reply

Here is a useful (to me, at least) Hydrology and Earth System Sciences open article on spatial and temporal downscaling of climate change model output.

Information on extreme precipitation for future climate is needed to assess the changes in the frequency and intensity of flooding. The primary source of information in climate change impact studies is climate model projections. However, due to the coarse resolution and biases of these models, they cannot be directly used in hydrological models. Hence, statistical downscaling is necessary to address climate change impacts at the catchment scale.

This study compares eight statistical downscaling methods (SDMs) often used in climate change impact studies. Four methods are based on change factors (CFs), three are bias correction (BC) methods, and one is a perfect prognosis method. The eight methods are used to downscale precipitation output from 15 regional climate models (RCMs) from the ENSEMBLES project for 11 catchments in Europe. The overall results point to an increase in extreme precipitation in most catchments in both winter and summer. For individual catchments, the downscaled time series tend to agree on the direction of the change but differ in the magnitude. Differences between the SDMs vary between the catchments and depend on the season analysed. Similarly, general conclusions cannot be drawn regarding the differences between CFs and BC methods. The performance of the BC methods during the control period also depends on the catchment, but in most cases they represent an improvement compared to RCM outputs. Analysis of the variance in the ensemble of RCMs and SDMs indicates that at least 30% and up to approximately half of the total variance is derived from the SDMs. This study illustrates the large variability in the expected changes in extreme precipitation and highlights the need for considering an ensemble of both SDMs and climate models. Recommendations are provided for the selection of the most suitable SDMs to include in the analysis.

What is potentially useful to me is that they went to a one day time scale, and they defined an “extreme precipitation index” for storms expected to happen once a year or less on average. I am interested in how or whether these concepts can be applied to “typical” hydrologic conditions that happen at the more-than-once-a-year level. Drought and flooding are probably the two most concerning conditions impacted by climate change, but there are also questions being asked about water quality, and it is the “typical” conditions that most come into play.