I really wanted to do a new hike blog but I have been trapped here by the heat. (I suppose I could do a blog about a night hike but there would be no photos.) The weather has been insane, with temps constantly in triple digits since early June (it is now August 7.) A few days ago the high was “only” 102 and we commented on how comfortable it felt and joked about the “cold snap”. Too many days in the hundred and tweens and teens.
Hottest day this year so far was 117F. Yesterday was 111 and the humidity was in single digits. Lately, it has been a hundred by noon and stays that way until after 6pm. We have had one decent winter in the last decade. This kind of weather is unheard of in SoCal. We know we are on the edge of the desert but it appears the desert has come to us.
During dry weather, the hotter parts of the region have a 35-40 degree difference between high and low. So if the Woodland Hills average is 83.8, the average high is going to be in the 100s and the low is going to be in the 60s. Wetter areas will be moderated by greater humidity and onshore wind flow. Everything here is about 5-10 degrees above the old “normal”. Also, notice how many all-time high records are recent. 2006 was a hot year. Most years in the past we would have highs in the 90s with short periods in triple digits where I live. Those triple digit temps persisted from late June through midAugust this year
Monsoonal moisture would also moderate those temperatures but we haven’t had much of a monsoon this year. In my memory, we have usually gotten measurable precipitation every month of the year. June is usually characterized by what we call “June gloom”, clouds, humidity, and occasional drizzle. Very little of that this year. Them July- September we would occasionally get summer thunderstorms where moisture would get pumped up from the Gulf. This would then get lifted by mountains or hot desert updrafts to create Cumulonimbus clouds tens of thousands of feet high. So far this year only the deep desert and high mountains have gotten any of this action.
If this weather keeps up – and I have no reason to think that it won’t – much of our local forest will burn and not come back. It was sprouted when times were moister and cooler. Pines will be replaced by oaks and oaks will be replaced by chapparal. Chapparal will be replaced by Mojave desert communities and the Mohave desert will be replaced by the Colorado desert. The Colorado desert will look more like Death Valley. Southern California will resemble Phoenix more than what it looks like today.
The various biomes will move higher in elevation and northward. Every thousand feet of elevation gain is another 3.5 degrees F cooler. At our latitude, every degree of latitude north (70 miles) is another degree F cooler.
Even a three-degree shift would kill off huge areas of deciduous and evergreen forest and they would burn. I can’t predict the exact amount of the shift over a specified time but it is pretty obvious some increase is still ahead of us. It will happen even if the world were to zero out anthropogenic greenhouse gas emissions right now. We still have to deal with these consequences. Vast humanitarian crises of unseen levels and urgency. Economic problems at home.
You can’t shift the temperatures 3 degrees without shifting precipitation patterns. Now imagine a 3-degree increase in temps with a 30% increase in rain. Low lying areas become marsh or swamp. More flooding of creeks and rivers. Fungus and blight become bigger problems. Your corn and wheat still fail. Drainage becomes crucial. Not to mention tropical diseases moving into the subtropics of the US.
More rain less snow, longer growing seasons, some places desertify, some places swampify, more diseases. What does well in Kentucky may need to be grown in Michigan and what does well in Florida may have to be grown in Maryland. The Everglades may expand, ocean levels rise a few inches and more strong hurricanes make landfall.
OTOH a lot of the West may end up be dryer. The climate of the Dakotas may just shift up to Manitoba. Some areas along the permafrost line will start to grow trees. The Alaska farm sector may expand. Greenland could once again become green and England could grow lots of grapes. Malaria could enter the South. The desert SW could become even desertier. Or the monsoons could send more water (and humidity) that way over the summer.
What we have now may not exist in ten years. It will be different. Don’t know how much.
California has been in a decades-long drought. Huge tracts of forest where the pines have been weakened and killed by the bark beetle. That feeds into vast wildfires. Those forests aren’t coming back because the climate that created them doesn’t exist anymore.
When a drought lasts for decades, it isn’t a random fluctuation. That is what is killing the SW US right now. What happens is that little changes keep piling up until a big change happens, a tipping point. Like maybe the high-pressure system over Nevada and Utah that gives us hot and dry weather in California is better able to stop systems coming in from Hawaii or Alaska from coming in and raining or cooling us.
Climate change can happen on shorter time scales than people think. You can have long-term stability, then a period of instability, then a period of stability with different conditions. In biology, we call this punctuated equilibrium. I don’t believe it is possible to separate anthropogenic climate warming from natural warming with any accuracy. We’ve been warming since the end of the Little Ice Age in the 1800s.
Think of water. Water is ice at 32F. Seawater freezes at 28.4 degrees. Then raise it one-tenth of a degree and it becomes liquid. (That tiny increase represents a huge heat energy, so it doesn’t happen quickly.) A fraction of a degree gain over an extended time can make big differences in ice pack over large areas. That changes the albedo of the earth over those areas making then much warmer than one might have predicted. The same thing happens to glaciers and mountain snow caps and to polar ice caps. Keep that up consistently for a few decades and things start to cascade.
OTOH the Little Ice Age was preceded by the Medieval Warming Period where it was much warmer (at least in the northern hemisphere) than today. England was a major grape producing country and the Vikings had farms and raised livestock in communities that are only now beginning to become visible as the Greenland ice pack melts. And before that an era of cool temperatures. Before that was the Roman Warm Period, again with temps similar to today.
Looked at a longer scale, we’ve been warming since the end of the Pleistocene when the Midwest US was under a mile of glacier ice. Any scientific model of such a complex process sinks into the quagmire of chaos theory. I do not doubt that the principles of the greenhouse effect are true, I just doubt the numbers are accurate enough for specific predictions. (I.E. say, 1 degree of natural warming over ten years and 2 degrees of anthropogenic warming.) I am only willing to state that significant amounts of each are clearly going to happen over time frames within the short period left in my life.
I am not saying we aren’t contributing to the heat. I’m saying anyone who claims to know to the exact degree is overstating their data. I have no patience at all for warming deniers.
I’m not thinking about the end of the world here. Just that mosquitoes from the tropic find our subtropics a bit more favorable and BANG, we have malaria and other tropical diseases invading. Or maybe the farming states might just have to look at different crops suitable for a longer but drier growing season. Other places have to worry about longer but wetter seasons. Coastal property more vulnerable to storm surge.
There are some nations that global warming will destroy. There are others that will benefit. (Think about Denmark) In the long run, I think the US will come out even but in the short run, there will be serious economic and environments problems.
Or maybe the snow cap on the Sierra is a lot less which has effects far beyond merely changing the biome. The farmers in the San Joaquin Valley need MORE water because it’s been getting hotter over the last few decades and because less snowcap means the groundwater can’t recharge as much so you have to go much deeper to find it. River levels drop as they are created from run-off. The water you are allowed to pump is further reduced because of the increased demand from large urban areas who easily outvote farmers when it comes to water policy.
Groundwater can run out. In some places, we’re pumping fossil water that has been there millions of years. When it is gone, there will be no replacement.
California south of Sacramento CAN become a dust bowl. All it takes is for farmers to walk away from their land instead of switching to low water demand crops and extremely high-efficiency delivery systems. It has happened before.
I have no doubt that we will get thru this. There is tremendous geographical diversity in the US so shifting food crops a few hundred miles north is practical. Only a very small percentage of land is actually used for growing food, large portions of that are exported and we are incredibly wasteful of the food we keep. Agriculture can still get far more efficient with water and so can people. For every area getting less water, others will get more. Hot and wet is good for crops and water could become an export item for those with too much. Expect massive desalination plants in our future.
The transition will be rough. Politicians will keep their heads buried in the sand until a crisis happens. Strap yourself in folks, for the next few decades, it is going to be a wild ride.