Name: Video 5.4: Climate Change, Water and Health
Uploaded: 2017-01-30T20:21:42.439Z
Duration: 14 min 2 s
Description: Watch this video about Video 5.4: Climate Change, Water and Health for Outcomes: Improved Water Services in Water Supply and Sanitation Policy in Developing Countries Part 1: Understanding Complex Problems.

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Climate change is one of the main factors or drivers

in the dynamic baseline, along with economic growth and demographic changes.

Water and sanitation policy interventions will

occur in a world with increasing temperature.

Sea level rise and more extreme weather events.

For water sanitation and hygiene sector professionals, it's

important to consider the question of whether wash

investments will be more or less effective or

economically attractive in a world with a changing climate.

The consequences of climate change for the water supply and sanitation sector are

complex and multifaceted, and [UNKNOWN] the answer to this question is not clear.

In this video and the next, we're going to

look at the effects of climate change from two perspectives.

First, in this video, we'll look at the effects of

climate change, health and water from the perspective of the household.

In the next video, we'll look at the effects

of climate change from the perspective of a water utility.

Two of the principle economic benefits from water and sanitation investments

are the reductions in mortality and

morbidity risks compared to baseline conditions.

But these baseline conditions are revolving due to climate change.

How climate change will affect these

baseline health conditions is still uncertain.

The question of how climate change will affect public health is a huge

and complex topic, one which we cannot explore in depth in this MOOC.

But, as current and future professionals in the

wash sector, we do want to encourage you

to think carefully about climate change and health

from both the household and the utility perspective.

We especially want you to reflect on how challenging it is to predict

how households will respond or adapt to the increased risks of their health.

And what this means for the economic

evaluation and selection of water and sanitation investments.

This figure shows eight pathways through which climate

change may affect a household's health and well-being.

The size of the arrows here suggests some preliminary

estimates of the size or importance of these pathways.

But these are highly uncertain, and likely to change from one location to another.

Note that most of these 8 pathways involve water.

If you look at the problem from a poor household's perspective, you can

see how difficult it is to adapt to so many increased health risks.

There are so many pathways, the effects are

uncertain, and the payoff from adaptation measures is uncertain.

Water and foodborne infections may increase due to higher temperatures.

Increasing the chances of household members getting sick.

This is especially a problem for poor households who lack refrigeration.

Increased temperatures and changing rainfall patterns may expand the

range of vector born diseases such as malaria dengue.

These risks may increase if more irrigation is

needed to adapt to erratic or less rainfall.

If increased temperatures and more erratic rainfall, decrease crop yield, this may

decrease the food supply of poor

subsistence households, leading to reduced health.

Increased temperatures will lead to increased crop water requirements.

Irrigation may be an important adaptation measure.

>> But a house hold will need money for this.

Increased temperatures may directly affect health through heat stroke.

Increased temperatures and increasing health risks will hit some

occupations, such as those that require outdoor labor, especially herd.

For example, for farmers and unskilled laborers, working outside during the heat

of the day is going to become increasingly difficult as temperatures rise.

Drinking and cooling water requirements for

laborers will increase and productivity will fall.

Wages may adjust downward.

There is increasing evidence too that

rising temperatures increase violence and civil conflict.

These effects are added to the stresses associated with floods and droughts.

A household may move or try to protect themselves from crime.

Note, that to the extent that climate change

contributes to migration, this may be a reason

not to increase in investments in water and

sanitation infrastructure in locations that are left behind.

Extreme weather events such as typhoons and

droughts directly threaten the lives of household members.

The risk of fires will increase in many areas.

Households have multiple ways to adapt to extreme events.

Including the purchase of insurance, moving to better

locations and increasing liquidity, to deal with emergencies.

Another important link between climate change

and health, is through air pollution.

And higher temperatures exasperate air pollution.

Particularly ozone and fine particulate matter, which

has a large, adverse effect on health.

Including respiratory disease associated with ozone and cardiopulmonary disease.

And lung cancer associated with particulate matter.

This next slide shows that the size of the effects

from these different pathways will increase by 2030 to 2040.

If no adaptations measures are taken.

This is based on estimates by the IPCC Working Group

II on health from both the literature and from expert judgement.

Water and sanitation investments are one adaptation method

that can address some of these adverse effects.

For example, pipe water services may enable

a household to irrigate a home garden.

To reduce the effects of malnutrition.

Improved household sanitation will likely become more important

as food contamination increases due to higher temperatures.

But, there are other climate change and public health

pathways that wash investments can do little to alleviate.

This next slide show that the magnitude of these health effects are

likely to increase over time if mitigation and adaptation measures are not adopted.

As shown, after the malnutrition pathway, the direct adverse

effects of increased temperatures on health are increasingly important.

Access to pipe water supplies can help household members

keep cool through increased opportunities for baths and showers.

Bringing water sources outside the home closer to dwellings

will reduce collection times and the exertion of household members.

Especially during periods of high heat.

But pipe water in the home will likely become

an increasingly important priority to households as temperatures rise.

In this slide, the arrows show how the size of the effects may increase

from the present state, shown in yellow, to that of 2030 to 2040 showing orange.

Enter 2080 to 2100 shown here in red.

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This light shows the magnitude of the effects through

the different pathways without additional adaptation shown in red.

And how these could be reduced with a high level of adaptation shown here in blue.

But all these calculations are highly uncertain.

They're really just educated guesses.

We now turn to one of the eight

pathways through which climate change can affect health.

The food and water borne infections pathway.

Wash professionals are especially concerned how

climate change might affect water borne diseases.

What do we know about how increased temperatures

and increased precipitation affect the incidences of diarrhea?

It turns out that this is not an easy question to answer.

Nor as we've emphasis is it likely to

be the pathway of greatest concern to the household.

One reason that this is not an easy question

to answer is that Diarrhea is caused by multiple pathogens.

These different pathogens will respond in different

ways in increases to temperature and precipitation.

For example, diarrhea caused by bacteria and protozoa tend to peak in and

warmer seasons while viral diarrhea cases tend to peak in cold and dry seasons.

Also, the relative importance of different pathogens

will vary from one location to another.

Diarrheal incidents often has stink seasonal patterns.

This slide shows seasonality in the pattern of

hospital admissions of Peruvian children for all-cause diarrhea.

As shown, admissions tend to increase

when temperatures increase and humidity decreases.

This is an arid setting where rainfall is low all year round,

but in other settings, rainfall has

been significantly associated with diarrheal disease.

Thus to the extent that climate change affects seasonal

temperature, rainfall and humidity patterns,

diarrheal incidence may be affected.

This next slide show seasonal patterns in norovirus cases in China and Germany.

The vertical axis shows the proportion of cases normalized by

location over all years for each study presented by month.

The pattern is most pronounced in Germany, where Norovirus

cases increase and peak in the winter when temperatures fall.

This is the opposite seasonal pattern from diarrheal cases in

Peru, where it is likely that bacterial and/or protozoan pathogens dominate.

Warm temperatures might first decrease the number of norovirus cases or affect

the relative dominance of different pathogens

in a location at different seasons.

These patterns illustrate the spacial

heterogeneity of diarrhoeal seasonality where local

weather patterns, geography and other

factors affect diarrhoeal incidents over time.

This slide presents a third example of seasonality

in water borne disease incidents, this time for cholera.

The figure on the left shows monthly cholera deaths in

Dakar between 1893 and 1940 from historical reference for India.

The typical seasonal pattern exhibits two peaks a year.

And is modulated by longer cycles with considerable

variation in total depths from year to year.

The figure on the right shows average monthly changes in cholera

cases from Bengal and Madras which have two peaks per year.

Both regions have high annual rainfall.

The shift shown in the bimodal seasonal cycles in Bengal and Madras.

Depends on the seasonal timing of the southwest mong,

monsoon in Bengal and the northeast monsoon in Madras.

Also shown is the Punjab which has drier climate and a single color peak per year.

Again these data show distinct patterns in disease incidence and weather.

Suggesting that climate change is likely to affect

the timing and patterns of disease in complex ways.

This final slide summarizes the results

from several studies that have investigated

the relationship between mean ambient temperature

in degree celsius and diarrheal disease.

The figure show the estimated percent

increase in relative risk of diarrhea cases.

Often this is hospital admissions.

Incidents or zed scores associated with each

1 degree celsius increase in mean ambient temperature.

Single empirical studies are shown in black, meter

analyses summarizing multiple studies are underlined in blue.

These studies use different models, time

stamps, and control for different covariants.

So they should be compared with caution.

The six studies summarized in the top half of the

figure used all cause diarrhea

or infectious gastroenteritis for their outcomes.

The three studies in the bottom half report results for rotavirus.

Since the six studies summarized in the top half

are not pathogen-specific the causes for diarrhea may include protozoa.

For example Giardia, Crytosporidium, or bacteria, for example, E

Coli, or Campylobacter, or viruses, for example Rotavirus and Norovirus.

The results for all cause diarrhea suggest a three to 11% increase

in cases with each one degree celsius increasing in mean ambient temperature.

However, one matter analysis by Lloyd and Co authors from 2007

did not find a significant relationship between temperature and diarrheal disease.

However, this study used large annual or multi annual study length time

steps instead of shorter weekly or monthly time steps like the individual studies.

and found rainfall to be significant.

Two of the rotovirus studies, both Gigiatahl and

leviatahl, found a negative correlation between temperature and rotovirus.

This corroborates the general findings that

rotovirus cases expand in colder months.

Likely because of greater time spent indoors.

With the hypothesis being that part of the transmission is through inhalation or air.

Rotavirus seasonality is similar to norovirus

seasonality that we observed in prior slides.

However, one study by Hashizume et al, in 2008,

reports nonlinear threshold effects for rotavirus at high temperatures.

They found that above 29 degrees celsius, there was a 40% increase

in rotavirus cases with each additional

one degree celsius increase in temperature.

Because bacteria and protozoa incidents increases in warm temperatures,

all cause diarrhea results, albeit biased, towards the null hypothesis.

Of no effect when there are multiple pathogens contributing to the outcome.

The bottom line here is that there is a lot of

variability in the results and lots of different factors at play.

A key message from this video is

that understanding households budget priorities and a demand

for improved water and sanitation services in a

world of climate change will become increasingly challenging.

Water and sanitation investments are likely to

be an important adaptation measure in many circumstances.

But this can not simply be assumed because households will have

so many adaptation needs, and priorities will be different in different locations.

There is still a great deal of uncertainty

about the effects of climate change on waterborne diseases.

Higher temperatures are likely to increase diarrhea cases modestly.

But there is likely to be a great deal of spatial and

temporal heterogeneity in the effects of climate change onwards to borne diseases.

Some of effects from the various pathways discussed in this video can be

dealt with at the household level but others must be addressed by the State.

But all the adaptation measures, whether paid for

by the household or by the state require money.

Thanks for watching this video.

Video 5.4: Climate Change, Water and Health

Water Supply and Sanitation Policy in Developing Countries Part 1: Understanding Complex Problems

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